Answer:
D). Reaction.
Step-by-step explanation:
Characterization is exemplified as one of the most significant tools through which the author provides shape, direction, and progress to the story by providing efficient details about the characters through which the events are efficiently described so that the audience could connect with it. The authors employ direct and indirect characterization depending upon their purpose.
Indirect characterization is demonstrated as the characterization technique in which the personality or traits of a character is not directly stated but rather reflected through his/her actions, looks(appearance), and speech.
As per the question, the type of indirect characterization employed in the given excerpt would be 'reaction' as Greg' 'straining', 'moved a step closer' and 'holding his breath reaction' reflects that he had a fear with darkness and had a problem with 'seeing in the dark'. Therefore, option D is the correct answer.