Answer:
+ D, by revealing the characters actions
Explanation:
While I'm not entirely sure that this is the correct answer, it seems like the most probable option.
A doesn't make sense, no internal thoughts are given
B could work, but we only get a small snipet of the character's words, and without context they do not really make sense.
C refers to a description/explanation of a theory/ idea, neither of these are given
D most of the story is made up of the character's actions, they seem a bit paranoid/frantic, as well as a tad temperamental