Great question! Brcibake's reasoning is on point.
There are two relevant rules we need to focus on to solve this one.
First, the rule that T cannot be mentioned in chapter 1.
Second, the rule that T must be mentioned before W and exactly two chapters must separate T and W. This rule gives us a block of four chapters that looks like this: T _ _ W.
Under the original rules of the game, if T is placed in chapter 1, W will be in chapter 4, since W always has to come 3 chapters after T.
Question 11 asks for a rule that will have the same effect on the game even if rule #1 (T cannot be in chapter 1) is suspended. We can get the exact same effect by creating a rule that W cannot be in chapter 4. Since T must always come 3 chapters ahead of W, if W cannot be in chapter 4; T still cannot be chapter 1. That's how we get (B) as the right answer.
I hope that helps clarify things. Good luck studying!