The correct answer is D. The main character chooses to follow his own path.
Step-by-step explanation:
In this story, the main conflict is the opposition between Green and Reds and the need for the main character to choose one side, this is explained in "Are you with the Greens or are you with the Reds? That question had been haunting him". Moreover, the final reaction of the character is simply to not choose any of the sides "he left the two warring clans behind forever" and simply continue with his life and own path. This is the action that solves the conflict because after some time the war between Greens and Reds is no longer important for the main character and he does not care about choosing any side.