Didn't get your explaination hardworker. Here is my logic...
X's arguement depends on peoples reaction being irrational. He supports it with an anology of 4 aces. In short he is saying that people shouldn't panic, because if occured once, the event has a lesser chance of happening in the future (unless it happens more frequently).
Y provides a counter agruement on rational and supports that even if the event has occured once, people take preventive action so that it doesn't happen in the future.
In short doesn't buy the "chance" logic of X and that an event happened once is sufficient enough for people to act, not its frequency (which makes it more probable to happen).
E is closest to the logic. B takes into account peoples reactions, support for which is hard to find in the set nof arguements.