A key source of self-confidence is ________.

A) comparing one's present performance to past failures
B) actual experience or things a person has done
C) observations of public figures
D) tweets one receives from family and friends

Actual experience or things a person has done is a key source of self-confidence as it provides tangible evidence of one's abilities and accomplishments. Comparing one's present performance to past failures may actually decrease self-confidence, and observations of public figures and tweets from family and friends may have little impact on personal confidence.