Positive psychologists believe that:

A) thinking in terms of catastrophes and defeat is important.
B) strengths such as optimism and perseverance cannot be learned through training.
C) everyone can overcome the barriers to self-development.
D) the strengths people build helps improve poor performance, but does not prevent such problems from happening in the future.

Positive psychologists believe in the growth mindset, which suggests that everyone has the potential to overcome barriers to self-development and improve their well-being. This approach emphasizes the importance of recognizing and cultivating our strengths rather than focusing on our weaknesses or failures. Therefore, the belief that everyone can overcome the barriers to self-development is a central tenet of positive psychology.