**Core Concept**
The lateral cutaneous nerve of the thigh is a branch of the lumbar plexus, responsible for providing sensory innervation to the skin over the lateral aspect of the thigh. It originates from the L2 and L3 nerve roots, forming part of the lateral femoral cutaneous nerve.

**Why the Correct Answer is Right**
The correct answer, **B. Supplies skin over the medial aspect of thigh**, is incorrect because the lateral cutaneous nerve supplies the skin over the lateral aspect of the thigh, not the medial aspect. The medial aspect of the thigh is innervated by the medial femoral cutaneous nerve, which arises from the L2 and L3 nerve roots as well. The lateral cutaneous nerve does not have a role in innervating the medial aspect of the thigh. This distinction is crucial for understanding the sensory innervation of the thigh.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is correct, as the lateral cutaneous nerve does indeed supply the skin over the lateral aspect of the thigh.
**Option C:** This option is correct, as the lateral cutaneous nerve arises from the L2 and L3 nerve roots, along with the medial femoral cutaneous nerve.
**Option D:** This option is correct, as the lateral cutaneous nerve is a purely sensory nerve, providing no motor innervation to the muscles of the thigh.

**Clinical Pearl / High-Yield Fact**
When examining a patient with a lesion in the lateral cutaneous nerve, it's essential to note that the sensory loss will be limited to the lateral aspect of the thigh, sparing the medial aspect. This distinction is crucial for diagnosing and managing peripheral nerve injuries.

**Correct Answer:**
✓ Correct Answer: B. Supplies skin over the medial aspect of thigh