**Core Concept**
Pulmonary embolism (PE) is a life-threatening condition characterized by the obstruction of a pulmonary artery by a blood clot, often originating from the deep veins of the lower limbs. The clinical presentation and management of PE are critical for patient outcomes.

**Why the Correct Answer is Right**
The most common symptom of pulmonary embolism is dyspnea (shortness of breath), not chest pain. Dyspnea is a direct consequence of the obstruction of blood flow to the lungs, leading to inadequate oxygenation of the blood. Chest pain, while present in some cases, is not the most common symptom of PE. The pathophysiology of PE involves the blockage of a pulmonary artery, which can lead to decreased perfusion of the lung tissue, resulting in hypoxemia and dyspnea.

**Why Each Wrong Option is Incorrect**
**Option B:** Most pulmonary emboli occur within 2-3 days of symptom onset, not within 2 weeks. The clinical presentation of PE can vary, but most cases are diagnosed within a shorter timeframe.

**Option C:** The statement is incorrect because the survival time does not directly correlate with the chance of recovery. In fact, the prognosis of PE is often poor, especially if the diagnosis is delayed or if the patient has underlying comorbidities. The outcome of PE is influenced by various factors, including the size of the embolus, the presence of underlying lung disease, and the promptness of treatment.

**Option D:** This statement is true, as most pulmonary emboli arise from the deep veins of the lower limbs, particularly the femoral and iliac veins.

**Clinical Pearl / High-Yield Fact**
A key clinical correlation for pulmonary embolism is the presence of a lower extremity deep vein thrombosis (DVT), which can be diagnosed using ultrasound imaging. The presence of a DVT increases the suspicion for PE and warrants further evaluation.

**✓ Correct Answer: A. Chest pain is the most common symptom**