How does the experience of reading a "Harry Potter" novel differ from the experience of watching a movie version of the book?

A)
In the first case, the reader knows what the characters look like; in the second case, he doesn't.

B)
In the first case, the reader cannot imagine anything; in the second case, he can imagine nothing.

C)
In the first case, the reader uses his or her imagination; in the second case, everything is put on visual display.

D)
In the first case, everything is put on visual display; in the second case, the viewer uses his or her imagination.