Which poison do they choose?

Use LaRon Landry and Sean Taylor to double team Randy Moss and Donte Stallworth … and leave the middle of the field vacated for Wes Welker.

Have Landry help cover Welker … and allow the speedy Stallworth to work in man coverage.

Blitz a safety or linebacker … and watch Tom Brady take advantage.

Never has the defensive to-do list been longer since Gregg Williams joined the Washington Redskins in 2004.

The statistics are eye-popping. In their 7-0 start, the Patriots are averaging 39.9 points and 432.9 yards, have punted 16 times, gone three-and-out 10 times, scored 41 touchdowns and outscored opponents by 159 points.

“Pretty much, from what I’ve seen, they do whatever they want,” Redskins defensive tackle Anthony Montgomery said. “If they want to pass it, they pass it; if they want to run it, they run it.”

Not since the 1999 St. Louis Rams, who averaged 34 points and 392.9 yards in their first seven games has the NFL seen such an unstoppable offense. Current Redskins associate head coach-offense Al Saunders was the Rams’ receivers coach during that Super Bowl season.

“Our guys had so much confidence in what we were doing and how we were doing it — we felt we could score every time we had the football,” Saunders said.

The Rams’ first loss was 24-21 to a Tennessee defense run by Williams.

The Patriots and Redskins both face their stiffest tests this week. New England has played one top-10 defense and five of the bottom six; the Redskins have faced two top-10 offenses.

As Redskins cornerbacks coach Jerry Gray admitted, “We haven’t faced anybody like these guys yet.”

As Brady admitted, “It’s really a different type of scheme than we’ve played against and we have some very unique challenges.”

To slow down the Patriots, the Redskins face three issues:

Problem No. 1: Who covers Randy Moss and how do you cover him?

Carlos Rogers (knee) and Fred Smoot (hamstring) are nursing injuries so it’s likely Williams will employ the “Cover 2” with Landry and Taylor.

The Patriots overhauled their receiving corps — signing Stallworth, trading for Moss and Welker — when it became apparent that sometimes even the best defensive game plan can’t slow down Indianapolis’ offense.

“When they tried to match up with Indy last year, they were short-handed,” Gray said.

Last year, New England was 11th in yards, 17th in yards a play, 12th in passing and seventh in scoring.

Enter Moss and Stallworth to give the Patriots downfield options. Moss has been reborn — 44 catches and a league-high 732 yards and 10 touchdowns.

“He’s a special skills guy,” Williams said of Moss. “He’s one of the rare ones in the league that plays above the goal post and he’s with a guy [Brady] that understands his skills.”

Stallworth has added 22 catches for 367 yards and three touchdowns.

Problem No. 2: How do you try to contain Wes Welker?

It depends what the Redskins do with Moss and Stallworth.

If they play “Cover 2,” Shawn Springs will cover Welker in the slot. If Welker is productive early, linebacker London Fletcher could help double team.

Two weeks ago at Dallas, Welker caught two touchdown passes. On the first, he beat a “bracket” double team (defenders inside and outside); on the second, the Cowboys zone blitzed and Welker ran a crossing pattern to easily beat defensive end Greg Ellis.

Welker has flourished in the Patriots’ system. Last year with Miami, he accounted for nearly 2,000 yards as a receiver and kick and punt returner. Incredibly, the Dolphins traded him to New England for second- and seventh-round draft picks.

Welker entered the season with 96 career receptions, he already has a team-high 47 this season. Those 47 catches have gone for 524 yards and five touchdowns.

“In a very short amount of time, he’s become maybe [Brady’s] favorite target,” Williams said. “He’s playing for the perfect coach right now that understands size doesn’t really matter. Bill’s done a great job of utilizing him. He’s made them very potent.”

Said Smoot: “He’s very good inside — that’s where he makes his living. With No. 12 throwing him the ball on time, he’s making plays.”

Problem No. 3: Is there even a point to blitzing Tom Brady?

Nope.

Brady has 229 pass attempts and been sacked only seven times. Like when the Redskins faced Green Bay’s Brett Favre, they could send 14 players and Brady would still get rid of the ball, either via the running back or a throwaway.

In the last three games, the Redskins have sent more than four rushers on one of 115 drop-backs.

“When you have a guy that can pull the trigger like a Peyton Manning or a Dan Marino, you’ve got a good team,” Gray said. “He makes great decisions, gets the ball where it needs to go and doesn’t throw a lot of interceptions.”

Five Patriots have at least 15 receptions, so Brady has confidence in a variety of targets. Early in the year, Moss was his favorite target; the last two weeks, it has been Welker.

Facing a team like the Patriots is why the Redskins made improving their secondary depth an off-season priority. Instead of Kenny Wright playing No. 3 corner, it will be Springs. Instead of Adam Archuleta wandering aimlessly through the secondary, Landry will get the start.

“I’ve seen them to be very focused,” Williams said of his defense. “The Patriots obviously have our attention. They understand the task they have. … They’re going to know what we do, we know what they’re going to do. It’s a match-up battle.”