We are looking for the one that could not be the three cities. We know that if H is in the fall, then T is in the fall. We also know that if V is in the spring, then T is also in the spring.
Lets look at (C), which is HVO.
If we put that HVO combination in the fall, that violates the rule that if HF -> MF, so HVO cannot be in the fall.
IF we put HVO in the spring, that violates the rule that if VS -> TS, so HVO cannot be in the spring. Thus, we can never have H, V, and O together.
