Final answer:
According to Bronfenbrenner's Ecological Model, the mesosystem is the system that most influences an individual who is born into a collectivistic culture and enters the adolescent stage of life.
Step-by-step explanation:
According to Bronfenbrenner's Ecological Model, the mesosystem most influences an individual who is born into a collectivistic culture and enters the adolescent stage of life. The mesosystem refers to the interactions and relationships between different microsystems, such as family, school, and community. In collectivistic cultures, where group and community values are prioritized, the mesosystem plays a significant role in shaping an individual's beliefs, behaviors, and socialization.