The answer is C. At first the child misjudges the elderly neighbor when he fears her, and is happy with their new friendship when she helps him.
A has misjudgment but no happiness.
B doesn't match at all
D doesn't say that the rivals misjudged their rivalry or were happy at any point.
A character arc is how a character changes and grows over the course of a story
Christian loves reading books, watching movies, and listening to songs.
That's an opinion, but other than that are you trying to make a point or is this a question?