**Core Concept**
Glomus tumors, also known as paragangliomas, are a type of neoplasm that arise from the paraganglia cells in the temporal bone. These cells are part of the parasympathetic nervous system and are involved in the regulation of blood pressure and heart rate. In the context of the external auditory meatus, a glomus tumor is a rare but significant tumor type.

**Why the Correct Answer is Right**
Glomus tumors in the external auditory meatus are known for their high vascularity and rich blood supply, which makes them highly pulsatile. They are also highly vascular, which explains why they bleed easily on touch. The tumor's rich blood supply is due to the presence of arteriovenous shunts, which allow blood to flow directly from the arterial to the venous side, bypassing the capillary bed.

**Why Each Wrong Option is Incorrect**
**Option A:** This option may refer to a different type of tumor, but it is not the most pulsatile tumor found in the external auditory meatus.
**Option B:** This option may refer to a different type of neoplasm, but it is not a tumor that is typically found in the external auditory meatus.
**Option C:** This option may refer to a benign growth, but it is not the most pulsatile tumor found in the external auditory meatus.

**Clinical Pearl / High-Yield Fact**
Glomus tumors in the external auditory meatus are highly vascular and can lead to significant bleeding on touch. It is essential to handle these tumors with caution and consider a biopsy or surgical excision to confirm the diagnosis.

**Correct Answer:** C. Glomus tumor.