Final answer:
According to aging expert Laura Carstensen, older adults tend to experience less intense positive emotions with new friends and equal levels of positive emotions with established friends. This is based on the socioemotional selectivity theory. The correct answer is older adults (option D).
Step-by-step explanation:
According to aging expert Laura Carstensen, older adults tend to experience less intense positive emotions with new friends and equal levels of positive emotions with established friends. This is based on the socioemotional selectivity theory, which suggests that as we get older, our social support and friendships dwindle in number, but remain as close, if not closer, than in our earlier years.
Erikson's theory of psychosocial development also explains that young adults (in their 20s through early 40s) are concerned with intimacy versus isolation. Developing a strong sense of self in adolescence is crucial before forming intimate relationships with others. Therefore, the correct answer is older adults (option D).