Answer:
a. Cognitions can be monitored, assessed, and changed
Explanation:
The underlying assumption of Cognitive Behavioral Therapy (CBT) is that cognitions, which refer to thoughts, beliefs, and patterns of thinking, can be monitored, assessed, and changed. This assumption is a fundamental principle of CBT, which focuses on identifying and modifying maladaptive thought patterns and cognitive distortions that contribute to problematic behaviors and emotional responses.