Topical. The topic is books and this text only focuses on books.
I am pretty sure b.transitional.
I think it is C) topical
it is topical because it is on one topic-cats. It is not a comparison, cats are not being compared to another animal. It is not transitional, there are no sentences that transition to another topic. and it isn't a process paragraph, there are no steps for any sort of action, such as making a cake