Answer: The third option, "Repression, projection, displacement, reaction formation, denial, and regression", are defense mechanisms.
Explanation: "Defense mechanisms" is a term used by Sigmund Freud to make reference to the psychological strategies that individuals resort to when trying to reduce anxiety or guilt. Some of the mechanisms are repression, projection, displacement, reaction formation, denial, and regression. These are also the ones in which Freud's daughter, Anna, concentrated on when she carried out her own research on the topic.