Psychologist george vaillant believed that a stage entered between the ages of 20 and 40, when young adults become centered on their careers is called

The stage is called  realistic period
 realistic period  refers to a time period when people started to value the things that would add a positive impact on their life such as career and personal relationship. During this time period, average people tend to became less adventerous and much less likely to go out and try some new tnings

Ithink the answer you are looking for is (b).