**Core Concept**
Pulmonary hypertension (PH) is a condition characterized by elevated blood pressure in the pulmonary arteries, leading to right ventricular failure and potentially life-threatening complications. This condition can result from various underlying causes, including left heart disease, lung disease, and thromboembolic disorders.

**Why the Correct Answer is Right**
Pulmonary hypertension is diagnosed based on clinical presentation and confirmed by right heart catheterization. Common signs and symptoms include dyspnea, fatigue, and syncope. Physical examination findings may include a loud P2 heart sound, peripheral edema, and a right ventricular heave. In severe cases, patients may exhibit signs of right heart failure, such as jugular venous distension and a pulsatile liver.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a specific sign of pulmonary hypertension. While dyspnea is a common symptom, it is not exclusive to PH and can be seen in various other conditions.
**Option B:** This option is incorrect because a loud P2 heart sound is a classic sign of pulmonary hypertension, resulting from increased pressure in the pulmonary arteries.
**Option C:** This option is incorrect because peripheral edema can be seen in various conditions, including left heart failure and nephrotic syndrome, and is not a specific sign of pulmonary hypertension.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that a loud P2 heart sound is a key physical examination finding in patients with pulmonary hypertension, and its presence should prompt further investigation, including echocardiography and right heart catheterization.

**Correct Answer: A. Dyspnea is a non-specific symptom of pulmonary hypertension.**