**Core Concept**
The Great Saphenous vein is located in the medial aspect of the leg, and its proximity to the saphenous nerve makes it susceptible to injury during venesection. The saphenous nerve is a sensory branch of the femoral nerve and provides sensation to the medial aspect of the leg.

**Why the Correct Answer is Right**
The saphenous nerve runs parallel to the Great Saphenous vein and is located superficially in the subcutaneous tissue of the leg. During venesection, the saphenous nerve can be damaged due to its close proximity to the vein. The saphenous nerve is responsible for transmitting sensory information from the medial aspect of the leg to the lumbar plexus.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the common peroneal nerve is located on the lateral aspect of the leg, which is not in close proximity to the Great Saphenous vein.
* **Option B:** This option is incorrect because the sural nerve is located on the lateral aspect of the leg and is not associated with the Great Saphenous vein.
* **Option C:** This option is incorrect because the femoral nerve is a major nerve that arises from the lumbar plexus and is not directly associated with the Great Saphenous vein.

**Clinical Pearl / High-Yield Fact**
The saphenous nerve can be damaged during venesection, leading to sensory loss in the medial aspect of the leg. This is an important consideration for surgeons performing venesection procedures.

**Correct Answer: C. Femoral nerve.**