**Core Concept**
Cubital tunnel syndrome is a type of nerve entrapment that occurs when the ulnar nerve is compressed at the elbow, leading to symptoms such as numbness, tingling, and weakness in the hand. This compression is often caused by repetitive flexion or extension of the elbow, leading to mechanical stress on the ulnar nerve.

**Why the Correct Answer is Right**
The compression of the ulnar nerve occurs at the cubital tunnel, a narrow passageway at the elbow where the ulnar nerve runs. The cubital tunnel is formed by the medial epicondyle of the humerus and the aponeurosis of the flexor carpi ulnaris muscle. When the elbow is flexed or extended, the ulnar nerve is subjected to increased pressure, leading to compression and subsequent symptoms. This compression is often exacerbated by activities that involve repetitive flexion or extension of the elbow, such as typing or playing musical instruments.

**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable, as this option is missing.
**Option B:** Incorrect, as cubital tunnel syndrome does not involve compression of the median nerve.
**Option C:** Incorrect, as cubital tunnel syndrome does not involve compression of the radial nerve.
**Option D:** Not applicable, as this option is missing.

**Clinical Pearl / High-Yield Fact**
Cubital tunnel syndrome is often referred to as "Saturday night palsy" due to its frequent occurrence in individuals who sleep with their elbows flexed, such as those who drink excessively or engage in other activities that impair motor control.

**Correct Answer:** C. Cubital tunnel syndrome involves compression of the ulnar nerve at the elbow.