Given: A is below E, B is below A, D is between A and E, and C is above D.

Arrangement (fixed order):

E is above D, D is above A, A is above B
So: E > D > A > B

Now place C:

C must be above D, so C can be:
1) Above E → C becomes the top book
2) Between E and D → E becomes the top book

Therefore, the book(s) that can be on the top: C or E