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
Deepest layer of deep cervical fascia is 
Select and explain. 
A. Prevertebral, B. Carotid sheath, C. Pretracheal, D. Temporal
A: Prevertebral
Answer: A: Prevertebral 
Explanation: Deep cervical fascia, also known as fascia colli is condensed to form 6 layers.

Investing layer.
Pretracheal layer.
Prevertebral layer.
Carotid sheath.
Buccopharyngeal fascia.
Pharyngobasilar fascia.

Prevertebral fascia:

It is the deepest layer of deep cervical fascia.
It lies in front of prevertebral muscles and forms the floor of posterior triangle of neck.
It is separated from pharynx and buccopharyngeal fascia by retropharyngeal space.