**Core Concept:** Finishing line is a slight reduction in thickness of a crown preparation intended to improve the marginal seal, reduce stress on the restoration, and facilitate cement retention. Full veneer crowns are designed to cover the entire visible surface of a tooth, requiring a more extensive preparation compared to partial veneer crowns.

**Why the Correct Answer is Right:** The correct answer, **D. Occlusal finishing line**, is placed in the occlusal (biting) surface of the prepared tooth. This type of finishing line reduces stress on the restoration due to the chewing forces, helps distribute the forces more evenly, and improves the marginal seal, contributing to better long-term success of the full veneer crown.

**Why Each Wrong Option is Incorrect:**

A. **Gingival finishing line:** This type of finishing line is placed in the gingival (gum) area, which is not the primary area of concern for full veneer crowns. The gingival finishing line may lead to an unsightly emergence profile and compromise the marginal seal, affecting the long-term success of the restoration.

B. **Occlusal and gingival finishing lines:** Placing both finishing lines in the gingival and occlusal areas would be redundant and unnecessary. A single occlusal finishing line is sufficient for full veneer crowns.

C. **Gingival and incisal finishing lines:** Placing finishing lines in both the gingival and incisal (incisor) areas would disrupt the esthetics and compromise the marginal seal, leading to poor long-term success of the restoration.

**Clinical Pearl:** A single occlusal finishing line is sufficient in full veneer crowns to achieve a functional, esthetic, and successful restoration. Avoid placing finishing lines in multiple areas, as it may lead to compromised esthetics and marginal seal.