This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thorax, Subject name: Anatomy
All of the following are true about phrenic nerve, except 
Select and explain. 
A. It is purely motor nerve, B. It arise from C4 spinal nerve, C. It is formed at the lateral order of scalenus anterior, D. Accessory phrenic is commonly a branch from the nerve of subcalvirus
A: It is purely motor nerve
Answer: A: It is purely motor nerve 
Explanation: The phrenic nerves contain motor, sensory, and sympathetic nerve fibers. The phrenic nerve originates mainly from the 4th cervical nerve, but also receives contributions from the 5th and 3rd cervical nerves Both phrenic nerves run from C3, C4, and C5 along the anterior scalene muscle deep to the carotid sheath. The accessory phrenic nerve is a branch of the nerve to the subclavius Ref: BD Chaurasia; 7th edition