Final answer:
Repression, denial, and reaction formation are defense mechanisms related to blocking threatening thoughts and memories from consciousness.
Explanation:
Repression is the defense mechanism responsible for obstructing threatening or unpleasant thoughts so that they remain outside of one's awareness. This mechanism involves keeping anxiety-related thoughts and memories in the unconscious.
Denial, another defense mechanism, involves refusing to acknowledge the existence of a threatening situation. For example, a person diagnosed with a serious illness may deny that the illness is real.
Reaction formation is when someone expresses feelings, thoughts, and behaviors opposite to their true inclinations, often to hide their true feelings. An example is someone being overly nice to a person they inwardly dislike.
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