**Core Concept**
Keisselbach's plexus is a vascular network located in the anterior aspect of the hard palate, in the region of the incisive foramen. This plexus is a collection of small blood vessels that are particularly prone to bleeding during dental procedures or trauma.

**Why the Correct Answer is Right**
The incisive foramen is a small opening in the anterior hard palate through which the nasopalatine nerves and vessels pass. Keisselbach's plexus is formed by the branches of the sphenopalatine artery, which enter the plexus through the incisive foramen. The plexus is a rich network of blood vessels that can easily bleed if damaged, making it a crucial consideration for dental surgeons and oral surgeons.

**Why Each Wrong Option is Incorrect**
* **Option A:** Keisselbach's plexus is not located in the posterior hard palate, which is closer to the palatine tonsils and uvula.
* **Option B:** The plexus is not associated with the greater palatine foramen, which is located in the posterior hard palate.
* **Option C:** Keisselbach's plexus is not related to the lesser palatine foramen, which is located in the soft palate.

**Clinical Pearl / High-Yield Fact**
It is essential for dental and oral surgeons to be aware of the location and potential for bleeding from Keisselbach's plexus, as this can lead to significant blood loss during procedures.

**Correct Answer:** C.