**Core Concept**
Impaired ventricular function refers to the heart's reduced ability to pump blood efficiently, leading to various clinical manifestations. This can be due to various factors such as coronary artery disease, cardiomyopathy, or hypertension.

**Why the Correct Answer is Right**
To determine the correct answer, let's analyze each option in the context of impaired ventricular function. We will consider the mechanisms and pathophysiology behind each clinical sign.

**Why Each Wrong Option is Incorrect**
* **Option A:** Pulsus paradoxus is a sign of impaired ventricular function. It refers to an exaggerated decrease in blood pressure during inspiration, often seen in conditions such as heart failure or severe asthma.
* **Option B:** Jugular venous distension (JVD) is a sign of impaired ventricular function. It occurs when the right atrium is unable to empty properly, leading to increased venous pressure and distension of the jugular veins.
* **Option C:** This option is not provided, so we cannot determine its accuracy.

**Clinical Pearl / High-Yield Fact**
In patients with impaired ventricular function, a key clinical finding is the presence of an S3 heart sound, which is a low-frequency sound heard during late diastole. This sound is caused by the rapid filling of the ventricles and is often a sign of heart failure.

**Correct Answer: D.**