**Core Concept**
Social anxiety disorder is a common mental health condition characterized by excessive and persistent fear of social or performance situations, leading to significant distress and impairment in daily functioning. This fear is often accompanied by symptoms of anxiety, avoidance behaviors, and negative self-perception.

**Why the Correct Answer is Right**
The medical student's symptoms of social anxiety disorder are evident in his excessive worry about being judged or criticized by his peers and tutors, leading to avoidance behaviors such as skipping bedside teaching. This pattern of behavior is a hallmark of social anxiety disorder, which is often triggered by performance-based situations. The student's fear of being judged is likely driven by a fear of negative evaluation, which is a common cognitive distortion in individuals with social anxiety disorder.

**Why Each Wrong Option is Incorrect**
**Option A:** Avoidant personality disorder is a distinct personality disorder characterized by pervasive feelings of inadequacy, social isolation, and avoidance of social interactions. While individuals with avoidant personality disorder may exhibit some similar avoidance behaviors, their primary motivation is a deep-seated fear of rejection and criticism, rather than a specific fear of performance situations.

**Option B:** Generalized anxiety disorder (GAD) is a condition characterized by excessive and persistent worry about everyday things, such as work, finances, or health. While individuals with GAD may exhibit some similar symptoms of anxiety, their worries are not specifically focused on social or performance situations.

**Option C:** Panic disorder is a condition characterized by recurrent panic attacks, which are intense episodes of fear or discomfort that reach a peak within minutes. While social anxiety disorder may co-occur with panic disorder, the student's symptoms do not suggest a primary diagnosis of panic disorder.

**Option D:** Obsessive-compulsive disorder (OCD) is a condition characterized by recurrent, intrusive thoughts (obsessions) and repetitive behaviors (compulsions). While individuals with OCD may exhibit some similar symptoms of anxiety, their symptoms are not specifically focused on social or performance situations.

**Clinical Pearl / High-Yield Fact**
Social anxiety disorder often co-occurs with other mental health conditions, such as depression, substance use disorders, or eating disorders. It is essential for clinicians to assess for these co-occurring conditions when diagnosing social anxiety disorder.

**Correct Answer: C. Panic disorder.**