This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
The axillary sheath is an extension of this fascia around the subclan aery and brachial plexus. Fascia around nerve bundle of brachial plexus is derived from: 
Select and explain. 
A. Preveebral fascia, B. Pretracheal fascia, C. Investing layer, D. Superficial cervical fascia
A: Preveebral fascia
Answer: A: Preveebral fascia 
Explanation: The brachial plexus and the subclan aery course between the anterior and middle scalene muscles, and as the nerve plexus and aery emerge from those muscles, they carry an extension of the preveebral fascia along to form the axillary sheath. Ref: Moon D.A., Foreman K.B., Albeine K.H. (2011). Chapter 26. Triangles and Root of the Neck. In D.A. Moon, K.B. Foreman, K.H. Albeine (Eds), The Big Picture: Gross Anatomy.