Since the last spots 4 and 5 receive the same type of wash, M cannot go in 4. If it did, spots 4 and 3 would be the same type of wash. Furthermore, according to the rules, spots 2 and 3 would match too. So spots 2,3,4, and 5 would all be the same type of wash leaving us with one spot and two types of washes left. Since all types of washes are used, this cannot happen.
O-r O - r
M-r M - r
These are the two possible scenarios. Right off the bat, you can see A) can't happen nor can C).
With D), the first three would all get r and (according the question stem) the last two must be the same two. So this would exclude one of the types of washes making it wrong. Also this proves that p must go to V and F and T get s.
V - p V - p
O - r 0 - r
M - r M - r
T - s F - s
F - s T - s
E) as you see isn't true either, consider V gets either r or p and F and T must be the same.
So B), is the only one that's possible.