**Core Concept**
Massive pulmonary embolism (PE) is a life-threatening condition characterized by a large blockage of the pulmonary arteries, leading to acute right ventricular failure and potentially fatal complications. The pathophysiology involves the sudden increase in pulmonary vascular resistance, which impairs right ventricular function and leads to decreased cardiac output.

**Why the Correct Answer is Right**
The correct answer is related to the clinical presentation and diagnostic features of massive PE. Massive PE typically presents with severe symptoms such as hypotension, tachycardia, and acute respiratory distress. The increased pulmonary vascular resistance and right ventricular failure lead to a characteristic electrocardiographic (ECG) pattern known as the "S1Q3T3" complex, where there is a prominent S wave in lead I and a Q wave in lead III, accompanied by a T wave inversion in lead III.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it is not a characteristic feature of massive PE. The "S1Q3T3" complex is a classic ECG finding in massive PE, whereas the "S1Q3T3" complex is not typically associated with Option A.
* **Option B:** This option is incorrect because it is a common cause of massive PE. Deep vein thrombosis (DVT) is a well-known risk factor for developing massive PE, and patients with DVT are at increased risk of developing a massive PE.
* **Option C:** This option is incorrect because it is a common complication of massive PE. Cardiac arrest is a potential complication of massive PE, especially if the right ventricular failure is severe and leads to a significant decrease in cardiac output.

**Clinical Pearl / High-Yield Fact**
Remember that the "S1Q3T3" complex is a classic ECG finding in massive PE, and its presence should raise suspicion for this diagnosis. However, it is essential to note that the ECG may not always be normal in patients with massive PE, and other diagnostic tests such as CT pulmonary angiography or ventilation-perfusion scan may be necessary to confirm the diagnosis.

**Correct Answer: C. Cardiac arrest**