**Core Concept**
Quinsy, also known as a peritonsillar abscess, is a rare but serious complication of tonsillitis. It involves the collection of pus in a specific location due to the anatomy of the tonsillar bed.

**Why the Correct Answer is Right**
The pus collection in quinsy typically gets collected in the peritonsillar space, which is the area between the tonsillar capsule and the superior constrictor muscle of the pharynx. This space is prone to infection due to its rich lymphatic supply and the fact that it is a common site for bacterial accumulation. The peritonsillar space is bounded by the tonsillar capsule medially, the superior constrictor muscle laterally, and the palatoglossal arch superiorly.

**Why Each Wrong Option is Incorrect**
* **Option A:** The parapharyngeal space is a potential space that can be involved in infections of the head and neck, but it is not the typical location for pus collection in quinsy.
* **Option B:** The submandibular space is another potential space that can be involved in infections, but it is not directly related to the tonsillar bed.
* **Option C:** The sublingual space is a potential space that can be involved in infections of the floor of the mouth, but it is not related to the tonsillar bed.

**Clinical Pearl / High-Yield Fact**
In cases of quinsy, it is essential to perform a thorough examination of the oropharynx to identify the location of the pus collection and to rule out other potential complications such as airway obstruction.

**Correct Answer: C. Peritonsillar space.