Why Does Self-Persuasion Work Better Than Being Lectured by Other

Why does self-persuasion work better than being lectured by other people to behave in a certain way?

A) Self-persuasion is based on implicit attitudes.
B) Self-persuasion takes place internally and involves convincing yourself of something.
C) Self-persuasion is automatic.
D) Self-persuasion is usually an effortful and conscious process that takes time.