For this question, we have a new rule, in addition to our original setup.
Our initial setup is
Wa: _ _ _ (Not P or Q) Fm: _ _ _ (Not S) Fa: _ _ _ (Not T)
and we are told that S and T are not together. I don't think I would set up scenarios here, so I would look at the answer choices and see which of them to prioritize. Since we know nothing about M, I would start by looking at B, C, and D.
For B, P being Fm tells us that T must be before it so we have T on Wa. We know that S and T cannot be together, so S must be on friday afternoon, so we have.
Wa: T _ _ (Not P or Q) Fm: P _ _ (Not S) Fa: S _ (Not T)
We also know the max we can put on friday afternoon is one, since there are only two things that could go Wa now, T and M, so we know Q is Fm, and thus M must be Wa. Since this is a valid scenario, B could be true.
Wa: T M _ (Not P or Q) Fm: P Q _ (Not S) Fa: S _ (Not T)