Lower lateral cutaneous nerve of arm is a branch of –
**Core Concept**
The question tests knowledge of the peripheral nervous system, specifically the **radial nerve** and its branches. The **lower lateral cutaneous nerve of the arm** is involved in supplying sensation to the lateral aspect of the arm.
**Why the Correct Answer is Right**
The **lower lateral cutaneous nerve of the arm** is a branch of the **radial nerve**, which originates from the **posterior cord of the brachial plexus**. This nerve is responsible for providing sensory innervation to the skin on the lower lateral part of the arm.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it is not related to the specific branch in question.
**Option B:** Incorrect as it does not pertain to the lower lateral cutaneous nerve of the arm.
**Option C:** Incorrect because, although related to the arm, it is not the correct branch.
**Clinical Pearl / High-Yield Fact**
The **radial nerve** is prone to injury, which can result in **wrist drop** or sensory loss on the back of the hand and the lateral 3.5 fingers.
**Correct Answer:** D. Radial nerve.