A. Jack, the leader of a gang of friends, is constantly challenged by Zack.
An external conflict is one that takes place between two opposing forces. The most common external conflicts are character vs character, character vs society, and character vs nature. This conflict is character vs character because Jack is challlenged by Zack. The two characters oppose each other.
Internal conflicts are conflicts within a person's mind or emotions. They usually involve the characters needing to make a difficult decision. All of the other options are internal conflicts.