C. Characterization.
"Characterization is a literary device that is used step-by-step in literature to highlight and explain the details about a character in a story. It is in the initial stage in which the writer introduces the character with noticeable emergence. After introducing the character, the writer often talks about his behavior; then, as the story progresses, the thought-processes of the character."
Answer:
The theme of the story is "trusting family and friends when you need them"
It is easy to identify the theme, since the main character goes through an ordeal when he gets lost; however, relying on a friend lets him find the way out of the situation.
Building long-life relationships is also shown in the story as a virtue, since the character had a shy personality and it was really hard for him to make friends.