Which of the following is an example of a common defense mechanism?

Projection is an example of a common defense mechanism because it involves attributing one's own unacceptable thoughts, feelings, or impulses to others. This can serve as an unconscious strategy to manage anxiety or guilt associated with those unwanted feelings. For instance, if someone has aggressive urges, they may accuse others of being hostile or unfriendly, thereby distancing themselves from their own feelings and reducing their internal conflict.

The other concepts listed, such as self-actualization, self-efficacy, and social learning, do not function as defense mechanisms. Self-actualization refers to the realization of one's potential and personal growth, self-efficacy involves an individual's belief in their ability to succeed in specific situations, and social learning relates to behaviors learned through observing others in a social context. These terms are more about personal development and learning rather than methods of coping with emotional stress.