Ben often acts so daring and overly confident that few people realize he is actually riddled with unconscious insecurity and self-doubt. Ben best illustrates the use of a defense mechanism known as

Reaction Formation

Explanation:

A Defense mechanism is a psychological strategy, development by the subconscious mind to protect us against fears or insecurities. Defense mechanisms are aimed at reducing the fears and anxieties.

Reaction  formation

Reaction formation is a defense mechanism that reduces anxiety or fear by showing the opposite feeling, impulse, or behavior rather than the real ones.

Ben acts overly confident and daring but within him, he has some doubts and insecurities. This made people most people to know him as bee confident, Ben was using reaction formation as his defense mechanism to hide his true behaviors by behaving in an exactly opposite manner.

i think it is the third one.