Explanation:
was the only one present who had said nothing. For some time he had sat silent beside Bilbo's empty chair, and ignored all remarks and questions. He had enjoyed the joke, of course, even though he had been in the know.
You are a careful reader is the correct answer
Paradox! "Make haste" means to hurry up, while slowly is the opposite, meaning with low speed. Therefore this two words/phrase contradict each other and the answer is a paradox.
Your asnwer is A :) :) :) :)