Final answer:
The correct indication for reflecting a flap that includes marginal gingiva is a facial perforation of a post in the coronal third of a root.
Step-by-step explanation:
The question concerns identifying an appropriate indication for reflecting a flap that includes marginal gingiva in a dental procedure. Among the options given, the correct indication is D. A facial perforation of a post in the coronal third of a root. When a perforation of this nature occurs, it is often necessary to reflect a flap, including the marginal gingiva, to gain access to the area for an effective repair. Marginal gingivitis, while being an inflammatory condition, does not typically require flap reflection for treatment. Similarly, procedures such as placing a porcelain-fused-to-metal crown or preparing an abutment for a fixed partial denture do not inherently require the reflection of a flap including marginal gingiva unless there are extenuating circumstances that necessitate such an approach.