**Core Concept**
Aortic regurgitation (AR) is characterized by the backflow of blood from the aorta into the left ventricle during diastole, resulting in an abnormal increase in ventricular volume. This condition can lead to various murmurs due to the altered hemodynamics.

**Why the Correct Answer is Right**
A pansystolic murmur is typically associated with mitral regurgitation, where blood flows back from the left ventricle into the left atrium throughout systole. In contrast, aortic regurgitation is characterized by diastolic backflow, making pansystolic murmur an unlikely finding in AR. The correct murmurs associated with AR are high-pitched decrescendo diastolic murmurs (Option A), soft, low-pitched mid-diastolic rumbling murmurs (Option B), and mid-systolic ejection flow murmurs (Option C), which are related to the increased flow and volume in the left ventricle.

**Why Each Wrong Option is Incorrect**
**Option A:** Not wrong, as it's a characteristic murmur of aortic regurgitation.
**Option B:** Not wrong, as it's also a characteristic murmur of aortic regurgitation.
**Option C:** Not wrong, as it's a mid-systolic ejection flow murmur, commonly heard in patients with aortic regurgitation due to increased flow across the aortic valve.

**Clinical Pearl / High-Yield Fact**
In patients with aortic regurgitation, the high-pitched decrescendo diastolic murmur is often described as a "blowing" sound, typically heard best at the left sternal border. The soft, low-pitched mid-diastolic rumbling murmur is often associated with the Austin Flint murmur, a classic finding in severe aortic regurgitation.

**✓ Correct Answer: D. Pansystolic murmur.**