In literature, characterization is the steps that a character in a narrative becomes fully realized or has completed an story arc. It is used to explain the details of a character in fiction. The answer is option B, the strenghts, weaknesses and motivations of the characters.
An example of characterization is when Don Quixote loses his mind after reading too many romances and comes to the realization that he is a knight destined to save his maiden from the forces of the giants (even though we know that he is delusional about the whole thing)