**Core Concept**
Pulsus bisferiens is a type of pulse characterized by two peaks, often associated with **aortic regurgitation** and **hypertrophic cardiomyopathy**. This condition reflects abnormal **ventricular ejection dynamics**.

**Why the Correct Answer is Right**
The correct answer is related to conditions where pulsus bisferiens is not typically observed. Pulsus bisferiens is commonly seen in aortic regurgitation due to the **rapid ejection of blood** into the aorta and then back into the left ventricle.

**Why Each Wrong Option is Incorrect**
**Option A:** Aortic regurgitation is a condition where pulsus bisferiens can be seen, making it an incorrect choice as the exception.
**Option B:** Hypertrophic cardiomyopathy is another condition associated with pulsus bisferiens, thus not the correct answer.
**Option C:** Aortic regurgitation and hypertrophic cardiomyopathy are conditions where pulsus bisferiens is seen.

**Clinical Pearl / High-Yield Fact**
Pulsus bisferiens is a significant clinical finding that can indicate underlying **cardiac pathology**, such as aortic regurgitation or hypertrophic cardiomyopathy.

**Correct Answer:** D.