**Core Concept**
Hangman's fracture is a type of traumatic injury to the cervical spine, specifically a bilateral fracture-dislocation of the C2 vertebrae. This condition occurs when there is a sudden and forceful hyperextension of the neck, often resulting from a high-impact injury such as a motor vehicle accident or a fall from a height.

**Why the Correct Answer is Right**
The correct answer is related to the mechanism of injury and the characteristic features of Hangman's fracture. Hangman's fracture is typically caused by a hyperextension injury, which leads to a bilateral fracture of the pedicles and pars interarticularis of the C2 vertebra. This type of fracture is often associated with a dislocation of the C2-C3 joint. The fracture is named after its resemblance to the knot used in hangings, with the two broken pieces of bone resembling the noose.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because Hangman's fracture is not typically associated with a unilateral fracture of the C2 vertebra.
* **Option B:** This option is incorrect because Hangman's fracture is not a type of compression fracture, but rather a fracture-dislocation injury.
* **Option D:** This option is incorrect because Hangman's fracture is not typically associated with a fracture of the C6 vertebra.

**Clinical Pearl / High-Yield Fact**
Hangman's fracture is a highly unstable injury that requires prompt and accurate diagnosis and treatment to prevent further neurological damage. It is essential to suspect Hangman's fracture in any patient with a cervical spine injury and to use imaging studies such as CT or MRI to confirm the diagnosis.

**Correct Answer:** C.