Question

The book seemed funny, thoughtful, and kept us interested. A. Change funny to amused us. B. Change kept us interested to interesting. C. No correction is needed.

Answer 1

B, change kept us interested to interesting.

Break up the sentence, then just use one section at a time to see if they all make sense.

The book seemed funny. That one makes sense.
The book seemed thoughtful. That one, too.
The book seemed kept us interested. That one, not so much… Interesting would fit better there.