**Core Concept**
Glue ear is a condition characterized by a thick, sticky fluid accumulation in the middle ear, leading to hearing loss and other complications. This condition is often associated with otitis media with effusion (OME), where the eustachian tube fails to drain the middle ear properly.

**Why the Correct Answer is Right**
The correct term for glue ear is otitis media with effusion (OME). This condition occurs when the eustachian tube, responsible for draining the middle ear, is blocked or dysfunctional. As a result, fluid accumulates in the middle ear, causing a range of symptoms including hearing loss, ear fullness, and decreased hearing acuity. The term "glue ear" is a colloquialism used to describe the thick, sticky nature of the fluid.

**Why Each Wrong Option is Incorrect**
**Option A:** Serous otitis media - This term is often used interchangeably with otitis media with effusion (OME), but it's not the most specific or commonly used term for glue ear.
**Option B:** Otitis externa - This is an infection of the outer ear canal, which is unrelated to the fluid accumulation in the middle ear.
**Option C:** Middle ear infection - While otitis media with effusion can be a complication of a middle ear infection, the two conditions are not the same.

**Clinical Pearl / High-Yield Fact**
When diagnosing glue ear, it's essential to consider the patient's symptoms, medical history, and physical examination findings. A tympanocentesis, where a sample of fluid is aspirated from the middle ear, can help confirm the diagnosis and guide treatment.

**Correct Answer:** C.