**Core Concept**
The retromolar pad is a crucial anatomical landmark in the fabrication of mandibular complete dentures. It is a small area located posterior to the last molar tooth and is essential for achieving proper denture retention, border seal, and stability.

**Why the Correct Answer is Right**
The retromolar pad plays a vital role in all three aspects of denture support: retention, border seal, and resistance to movement. Retention is enhanced because the denture base covers the retromolar pad, creating a larger surface area that comes into contact with the mucosa, thereby increasing the force of adhesion. A border seal is achieved as the denture base covers the retromolar pad, preventing the entry of air or fluid between the denture and the mucosa, which can compromise denture stability. Moreover, the retromolar pad helps to resist movement of the denture base by providing an additional point of support, thereby enhancing the overall stability of the denture.

**Why Each Wrong Option is Incorrect**
* **Option A:** While a larger surface area does provide better retention, it is not the sole reason for covering the retromolar pad. Other factors such as border seal and resistance to movement are equally important.
* **Option B:** A border seal is indeed achieved by covering the retromolar pad, but it is not the only benefit. Retention and resistance to movement are also crucial aspects of denture support.
* **Option C:** Resistance to movement is an important aspect of denture support, but it is not the only reason for covering the retromolar pad. Retention and border seal are equally important.

**Clinical Pearl / High-Yield Fact**
When fabricating mandibular complete dentures, it is essential to cover the retromolar pad to achieve proper denture retention, border seal, and resistance to movement. This can be achieved by using a border seal material or by incorporating a retentive area into the denture design.

**✓ Correct Answer: D. All of the above**