**Core Concept**
Whitnall's Tubercle is a bony prominence located on the lateral wall of the orbit, serving as an attachment point for the lateral palpebral ligament. It plays a crucial role in maintaining the integrity of the eyelid and its position relative to the globe.

**Why the Correct Answer is Right**
Whitnall's Tubercle is a small bony projection situated on the lateral wall of the orbit, specifically on the anterior aspect of the zygomatic bone. This prominence serves as the site of attachment for the lateral palpebral ligament, which helps to maintain the lateral canthus of the eyelid and prevent it from becoming too wide or too narrow. The correct location of Whitnall's Tubercle is essential for understanding the anatomy of the orbit and the surrounding structures.

**Why Each Wrong Option is Incorrect**
**Option B:** The medial wall of the orbit is primarily composed of the lamina papyracea of the ethmoid bone and does not contain Whitnall's Tubercle.

**Option C:** The roof of the orbit is formed by the orbital plate of the frontal bone and does not feature Whitnall's Tubercle.

**Option D:** The floor of the orbit is primarily composed of the orbital plate of the maxilla bone and does not contain Whitnall's Tubercle.

**Clinical Pearl / High-Yield Fact**
Whitnall's Tubercle is an important landmark in orbital anatomy, and its identification can aid in the diagnosis of periorbital fractures and other orbital pathologies.

**✓ Correct Answer:** A. **Lateral wall of Orbit**