**Core Concept**
Syndrome X, also known as microvascular angina, is a condition characterized by chest pain due to reduced blood flow to the heart muscle, despite normal coronary arteries. It is thought to be caused by abnormal function of the endothelium, leading to impaired vasodilation and increased vascular resistance.

**Why the Correct Answer is Right**
The correct answer is a combination of symptoms that are typically associated with Syndrome X, including chest pain, shortness of breath, and fatigue. These symptoms are thought to be caused by the reduced blood flow to the heart muscle, leading to ischemia and pain. The endothelium plays a crucial role in regulating blood flow and blood pressure, and abnormalities in its function can lead to the development of Syndrome X.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Syndrome X is not typically associated with an elevated troponin level. Troponin is a marker of cardiac muscle damage, and its elevation is often seen in conditions such as myocardial infarction.

**Option B:** This option is incorrect because Syndrome X is often associated with normal or near-normal coronary arteries on angiography. The condition is thought to be caused by microvascular dysfunction rather than large vessel disease.

**Option C:** This option is incorrect because Syndrome X is often associated with vasodilator-induced angina. This means that symptoms can be provoked or worsened by medications that dilate blood vessels, such as nitroglycerin.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Syndrome X is a diagnosis of exclusion, and a thorough evaluation is necessary to rule out other causes of chest pain. A normal coronary angiogram does not necessarily rule out the presence of microvascular disease.

**Correct Answer:** D