B. On the fire escape sit two stray cats
A general rule is that subject has to match verb.
(A) is wrong because one rabbit HOPS, not hop
(C) is wrong because two lands WERE at war, not was
(D) is wrong because they HAVE, not has
(B) is correct because two stray cats sit
*notice that when there's an "s" in the noun, or if the noun is plural, then the verb lacks an "s", and when there isn't an "s" at the end of the noun (it's singular), then the verb DOES have an "s". This is the rule of thumb (there are exceptions though)
