Cameron's decision to give up his summer vacation to help paint and repair the homes of aging citizens reflects a sense of responsibility and concern for the well-being of others. According to Kohlberg's theory of moral development, this behavior aligns with the Conventional Level, specifically Stage 3 (Interpersonal Relationships), where individuals focus on living up to social expectations and roles, and the importance of being seen as a good member of society.
Therefore, the correct answer is Conventional, Stage 3.