**Core Concept**
Chronic cough is a persistent cough lasting more than 8 weeks, often due to underlying respiratory or cardiovascular conditions. The pathophysiology involves the activation of various sensory receptors in the respiratory tract, leading to the cough reflex.

**Why the Correct Answer is Right**
The correct answer is **Persistent Cough as a symptom of Lung Cancer**. Chronic cough can be a presenting symptom of lung cancer, especially in non-smokers. The cough is often dry and non-productive, and may worsen at night. The mechanism involves the stimulation of cough receptors by tumor cells, leading to the activation of the cough reflex.

**Why Each Wrong Option is Incorrect**
* **Option A:** Chronic cough is not typically associated with **Pulmonary Embolism**, which usually presents with sudden onset dyspnea and chest pain.
* **Option B:** **Asthma** is a common cause of chronic cough, but it is not the correct answer as the question is asking for a symptom of another condition.
* **Option C:** **Gastroesophageal Reflux Disease (GERD)** can cause chronic cough, but it is not the correct answer as the question is asking for a symptom of another condition.

**Clinical Pearl / High-Yield Fact**
Remember that chronic cough can be a "hidden" symptom of lung cancer, especially in non-smokers. Always consider lung cancer in the differential diagnosis of chronic cough.

**Correct Answer:** C.