The crew, made of clowners and krumpers, have visited italy, hong kong, and france.

which subject-verb agreement rule is being broken in the sentence above?

The subject-verb agreement rule which is being broken in the sentence above is collective subjects functioning as a unit require singular verbs.
The collective subject the crew requires a singular verb, because it denotes a single unit. So, instead of using the verb have visited, it should have been has visited. 

B. alice is pretending there is a way through the glass when in reality that would not be physically possible therefore she has to pretend. but i think d is also possible because alice notices the glass is actually melting away which is also not possible either