The settling down period beings in the early 30s and lasts till the late 40s. Therefore the correct option is 33-39.
Daniel Levinson defines human life in several stages. He defined the age between 30s-40s as the settling down period as the individual desires to settle in his life and career.
He wants to make family and look after them. The only task is to become a full-fledged adult, which emphasizes stability and security.
Therefore the correct option is a.
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