**Core Concept**
Abduction of the hand refers to the movement of the hand away from the midline of the body, specifically the movement of the thumb and fingers away from the middle finger. This movement is primarily facilitated by the muscles of the forearm, particularly the muscles of the anterior compartment.

**Why the Correct Answer is Right**
The primary muscle responsible for abduction of the hand is the **Abductor Pollicis Longus (APL)**. The APL muscle originates from the posterior surface of the ulna and inserts into the base of the first metacarpal bone. When the APL contracts, it pulls the first metacarpal bone away from the midline of the hand, resulting in abduction of the thumb. This movement is essential for various daily activities, such as grasping and manipulating objects.

**Why Each Wrong Option is Incorrect**
* **Option A:** None provided, so no explanation is required.
* **Option B:** This option is not relevant to the movement of the hand.
* **Option C:** This option is not accurate, as the muscles of the posterior compartment of the forearm primarily facilitate supination and extension of the wrist.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the **Abductor Pollicis Longus (APL)** muscle is responsible for abduction of the thumb, whereas the **Abductor Pollicis Brevis (APB)** muscle is responsible for abduction of the thumb at the carpometacarpal joint.

**Correct Answer: B. Biceps Brachii**