**Core Concept**
Coarctation of the aorta is a congenital heart defect characterized by an abnormal narrowing of the aortic isthmus, typically located near the junction of the aortic arch and descending aorta. This narrowing leads to increased resistance to blood flow, resulting in hypertension in the upper body and hypotension in the lower body.

**Why the Correct Answer is Right**
The narrowing in coarctation of the aorta is usually located at the site of the ductus arteriosus, a fetal shunt that connects the pulmonary artery to the aorta. As a result, the ductus arteriosus often remains patent in patients with coarctation, allowing for collateral circulation to develop and alleviate some of the symptoms. The increased pressure in the upper body can lead to the development of hypertension, while the decreased pressure in the lower body can result in hypotension and potentially, decreased blood flow to the lower extremities.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the typical location of coarctation of the aorta.
**Option B:** This option is incorrect because it does not take into account the potential development of collateral circulation in patients with coarctation.
**Option C:** This option is incorrect because it does not accurately describe the relationship between coarctation of the aorta and the development of hypertension.

**Clinical Pearl / High-Yield Fact**
One key clinical feature of coarctation of the aorta is the presence of a "collapsing" pulse in the upper extremities, which is due to the increased resistance to blood flow. Additionally, patients with coarctation may exhibit a "rib notching" on chest radiographs, which is caused by the formation of collateral blood vessels that erode the lower borders of the ribs.

**Correct Answer: C.**