**Core Concept**
The "Great Hilar Dance" sign refers to a fluoroscopic finding associated with **cardiovascular pathology**, specifically related to the movement of the hilar structures in response to cardiac activity.

**Why the Correct Answer is Right**
This sign is typically seen in conditions where there is an abnormal transmission of cardiac motion to the hilar structures, such as in **mitral stenosis** or other conditions affecting the left atrium. The increased pressure and volume in the left atrium cause the hilar structures to move more noticeably with each heartbeat, creating the "dance" appearance on fluoroscopy.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not directly related to the transmission of cardiac motion to the hilar structures.
**Option B:** Incorrect as it does not typically cause the hilar dance sign.
**Option C:** Incorrect because it is not associated with this specific fluoroscopic finding.

**Clinical Pearl / High-Yield Fact**
The "Great Hilar Dance" sign is a classic fluoroscopic sign that can indicate **mitral valve disease**, particularly mitral stenosis, and highlights the importance of considering cardiac causes when evaluating hilar movement on imaging studies.

**Correct Answer:** D. Mitral Stenosis.