**Core Concept**
The pudendal nerve is a mixed nerve that supplies the external anal sphincter, among other structures, and is derived from the sacral plexus. Specifically, it originates from the S2, S3, and S4 nerve roots.

**Why the Correct Answer is Right**
The pudendal nerve is formed by the ventral rami of the S2, S3, and S4 nerve roots, which converge to form the pudendal nerve. This nerve then descends through the pelvic cavity, providing motor innervation to the external anal sphincter, as well as sensory innervation to the perineal region. The motor fibers to the external anal sphincter are responsible for controlling voluntary defecation.

**Why Each Wrong Option is Incorrect**
**Option A:** This option does not specify the correct nerve roots that contribute to the formation of the pudendal nerve.
**Option B:** This option is incorrect as the obturator nerve is primarily responsible for innervating the adductor muscles of the thigh.
**Option C:** This option is incorrect as the inferior gluteal nerve primarily innervates the gluteus maximus muscle.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the pudendal nerve is responsible for controlling voluntary defecation through its motor innervation of the external anal sphincter. This highlights the importance of the pudendal nerve in maintaining continence.

**Correct Answer: C. The inferior gluteal nerve primarily innervates the gluteus maximus muscle, not the external anal sphincter.