Concept:Obsessive-compulsive disorder (OCD) is classified as an anxiety disorder because it involves persistent, distressing anxiety that drives repetitive thoughts and actions.Explanation:OCD has two main parts: obsessions and compulsions. Obsessions are unwanted, intrusive thoughts that cause extreme anxiety. Compulsions are repeated behaviors performed to reduce that anxiety. For example, a person may repeatedly wash hands to neutralize a fear of germs. This cycle of anxiety and ritualistic behavior is a hallmark of anxiety disorders. Other options are incorrect: dissociative disorders involve detachment from reality, adjustment disorders arise from stressful life events, and somatoform disorders involve physical symptoms with no medical cause. OCD directly fits under anxiety disorders because the core problem is excessive, uncontrollable anxiety.Answer:C. Anxiety disorder