**Core Concept**
The bicipital aponeurosis is a fibrous expansion of the biceps brachii muscle, which plays a crucial role in stabilizing the elbow joint. It is a thickened fascial layer that covers the brachialis muscle in the cubital fossa.

**Why the Correct Answer is Right**
The bicipital aponeurosis lies over the brachialis muscle in the cubital fossa. This is because the brachialis muscle is the most superficial muscle in this region, and the bicipital aponeurosis serves as a fascial covering for it. The brachialis muscle is innervated by the musculocutaneous nerve and plays a key role in elbow flexion.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the lacertus fibrosus, a part of the bicipital aponeurosis, actually covers the median nerve in the cubital fossa, not the structure listed here.
**Option B:** This option is incorrect because the median nerve is a separate structure that runs through the cubital fossa but is not covered by the bicipital aponeurosis.
**Option C:** This option is incorrect because the brachial artery is a superficial structure in the cubital fossa, but it is not covered by the bicipital aponeurosis.

**Clinical Pearl / High-Yield Fact**
Remember that the bicipital aponeurosis forms the roof of the cubital fossa and serves as a landmark for the median nerve, which lies beneath it.

**Correct Answer:** C. Brachialis