What defense mechanism involves keeping an undesirable impulse out of awareness by emphasizing its opposite?

The correct choice highlights a defense mechanism known as reaction formation. This mechanism occurs when an individual consciously adopts attitudes or behaviors that are in stark contrast to their true feelings or desires. For instance, if someone harbors feelings of anger towards another person but instead displays exaggerated friendliness and affection, they are engaging in reaction formation. This serves to protect their psyche by preventing the expression of those undesirable impulses.

The mechanism's function is to maintain psychological equilibrium by transforming unwanted emotions into their opposites, a process that can help individuals cope with anxiety or discomfort associated with those feelings. In essence, reaction formation allows for a semblance of normalcy and social acceptability while concealing potentially distressing impulses.

By understanding this particular defense mechanism, one can gain insight into how individuals might navigate complex emotional landscapes, often employing such strategies unconsciously to regulate their emotional states and interactions with others.