## **Core Concept**
The question tests the understanding of anxiety disorders, specifically focusing on the diagnosis of conditions characterized by fears and anxieties related to specific situations or places. The key concept here involves identifying the type of anxiety disorder based on the described symptoms and behaviors.

## **Why the Correct Answer is Right**
The correct answer, **C. Agoraphobia**, is appropriate because the symptoms described—fear of leaving home, fear of traveling alone, fear of being in a crowd, and experiencing marked anxiety with palpitations and sweating in these situations—align closely with agoraphobia. Agoraphobia is characterized by anxiety about being in public places or situations where escape might be difficult or embarrassing, or where help may not be available in the event of having an unexpected panic attack or panic-like symptoms. The behavior of avoiding public transport to go to work further supports this diagnosis, as it indicates a significant impact on daily life.

## **Why Each Wrong Option is Incorrect**
- **Option A: Specific Phobia** - This option is incorrect because specific phobia involves a persistent and excessive fear of a specific object, situation, or activity. While the fears described are specific, they encompass a broader range of situations (leaving home, traveling alone, being in crowds) than what is typically seen in specific phobias.
- **Option B: Social Anxiety Disorder** - This option is incorrect because social anxiety disorder primarily involves fear of social or performance situations in which the person is exposed to possible scrutiny by others. The fear described in the question is more related to situations and places rather than social interactions.
- **Option D: Panic Disorder** - This option is incorrect because, although panic disorder involves recurrent panic attacks, it does not specifically involve the persistent fear of being in situations from which escape might be difficult or where help may not be available.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that agoraphobia often occurs in conjunction with panic disorder, but it can also occur independently. The essential feature of agoraphobia is the fear of being in crowds, public places, or situations where escape to a safe place might be difficult or embarrassing, or where help may not be available. A helpful mnemonic to remember is that agoraphobia involves fear of being in **"agora"** (market or public places), which captures the essence of the feared situations.

## **Correct Answer: C. Agoraphobia**