**Core Concept**
Aortic dissection is a medical emergency characterized by the tear in the inner layer of the aorta, allowing blood to flow between the layers and potentially leading to aortic rupture. This condition is often associated with hypertension, atherosclerosis, and genetic disorders.

**Why the Correct Answer is Right**
Aortic dissection typically occurs in the ascending aorta, which is more prone to hypertension-related damage. The tear in the intima can extend to the media or even the outermost layer, leading to aortic dilation and potential rupture. The condition often presents with severe chest pain, syncope, and hypotension. The most common cause of aortic dissection is uncontrolled hypertension, which can lead to aortic wall stress and potential dissection.

**Why Each Wrong Option is Incorrect**
**Option A:** Marfan syndrome is a genetic disorder that can cause aortic dissection, but it is not the only condition associated with aortic dissection.
**Option B:** Atherosclerosis is a risk factor for aortic dissection, but it is not directly responsible for the condition.
**Option C:** Hypertension is the most common cause of aortic dissection, but it is not the only condition that can lead to aortic dissection.

**Clinical Pearl / High-Yield Fact**
Aortic dissection is a medical emergency that requires prompt diagnosis and treatment to prevent rupture and mortality. The Stanford classification system differentiates between ascending (Type A) and descending (Type B) aortic dissections.

**Correct Answer: C. Hypertension.