Let's look at our last rule, that tells us that P is after O or L, but not after both. This means that one of P/L is before O, and one is after, so we either have L...P...O, or O...P...L. We know that L is either first or last, so we can set up two scenarios.
L _ _ _ _ _ (P >O) _ _ _ _ _ L (O>P)
In the second scenario we cannot have O be anywhere after 4, so lets look at the first.
We could try the following:
L T W Z P O
Since this could work, it is not necessarily true that two people dive after O , since O is last here, so B is not soemthing that must be true.
