Final answer:
Self-efficacy is strengthened by information from four sources: successful past experiences, observational learning, verbal persuasion, and physiological and emotional states.
Step-by-step explanation:
Self-efficacy is an individual's belief in their own capability to complete a task. According to Albert Bandura's theory of self-efficacy, it is strengthened by information from four sources. These sources include successful past experiences, observational learning, verbal persuasion, and physiological and emotional states.