The correct answer is D. How the author describes the character.
Step-by-step explanation
Indirect characterization is when the reader knows the attributes of a character through his speech, actions, reactions of other characters, and appearance that allow the reader to conclude the character's personality based on this information. According to the previous definition, the correct answer is "D. How the author describes the character" because the description made by the author would be a direct characterization in which the author or the narrator directly describes the traits of a character.