**Core Concept**
Coarctation of the aorta is a congenital condition characterized by the narrowing of the aortic isthmus, typically at the junction of the aortic arch and descending aorta. This narrowing leads to increased resistance to blood flow, resulting in hypertension above the coarctation and hypotension below it.

**Why the Correct Answer is Right**
The correct answer is related to the typical clinical presentation of coarctation of the aorta. Patients often exhibit hypertension in the arms, decreased or delayed pulses in the lower extremities, and may have a "rib-notching" appearance on chest radiographs due to collateral vessel formation. The presence of a murmur, typically a continuous murmur ("machinery" murmur) due to the flow through the collateral vessels, is also characteristic.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is a common feature of coarctation of the aorta. The narrowing of the aorta leads to increased resistance and subsequent hypertension above the coarctation site.
**Option B:** This option is incorrect because it is also a common feature of coarctation of the aorta. The decreased or delayed pulses in the lower extremities are due to the reduced blood flow below the coarctation site.
**Option C:** This option is incorrect because it is a classic radiographic finding in coarctation of the aorta. The "rib-notching" appearance is due to the formation of collateral vessels that supply the lower body.

**Clinical Pearl / High-Yield Fact**
A classic clinical finding in coarctation of the aorta is the "blood pressure difference" between the arms and legs, with higher blood pressure in the arms. This difference is often used as a diagnostic clue.

**Correct Answer: D**