Final answer:
Levinson's research does not specifically characterize the later 30s, focusing more broadly on adult transitions. Erikson's theory progresses from stages of intimacy versus isolation, to generativity versus stagnation, then to integrity versus despair without explicit reference to the later 30s.
Step-by-step explanation:
Levinson's Belief on Later 30s
Levinson and his colleagues did not precisely mention the later 30s as characterized by any of the options A), B), C), or D). Rather, their focus was on the concept of midlife transition, which could potentially lead to what many refer to as the midlife crisis. However, in the field of Psychology, particularly in the theory of psychosocial development proposed by Erik Erikson, the later 30s is not explicitly detailed as a separate phase. Instead, Erikson's stages progress from young adulthood focused on intimacy versus isolation, into middle adulthood which concerns generativity versus stagnation, and eventually leading to late adulthood which is characterized by integrity versus despair. In terms of Levinson's work, one could infer that the later 30s may still be a part of the adult transition where there is a struggle to balance life dreams with the reality of one's life situation, potentially leading to stable life structures and career adjustments.