Compulsions are defined as which of the following?

Compulsions are defined as repetitive behaviors or mental acts that an individual feels driven to perform in response to an obsession or according to rules that must be applied rigidly. The purpose of these compulsive actions is often to prevent or reduce anxiety or distress related to the intrusive thoughts or obsessions.

In this context, the correct choice identifies the behavior aspect of compulsions and acknowledges their connection to obsessive thoughts. They are typically viewed as attempts to mitigate the distress caused by those obsessions, thus serving as a means of coping, albeit often ineffective in the long term.

The other options, while related to anxiety and obsessive-compulsive behaviors in some broader sense, do not accurately define compulsions themselves. Intrusive thoughts denote the nature of obsessions, specific fears indicate phobias rather than compulsive actions, and worry refers to anxiety but does not involve the repetitive actions associated with compulsions. Therefore, the definition provided in the correct choice captures the essence of compulsions as behavioral responses dictated by the intrusive nature of obsessive thoughts.