Amotif is a) a metaphor that is developed over several sentences b) the way a character develops over the course of a story c) a summary of the main themes of a novel d) an image, idea, or theme that reoccurs throughout a novel

D) an image, idea, or theme that reoccurs throughout a novel

Explanation:

In literature, a motif can be defined as "any recurring element that has symbolic significance in a story". So it is not about character development, nor a metaphor (although, it can be depending on the context) or a summary. It is a unifying element that repeats itself.

the answer would be c