Answer:
I think the answer is B.
Step-by-step explanation:
It's possible that the answer is a, but I haven't read this book or story so I'm not sure, but I'm trusting you that it's not a. I think that the answer is b because usually, when people say that someone is crazy, they don't mean that they are crazy, they are just confused as to why the other person would do such a thing, or are unwilling to do the thing themselves, which is most likely the case for Happy saying the Biff is crazy.
Hope this helps!