This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharynx, Subject name: ENT
Which of the following is not true about acute retropharyngeal abscess 
Select and explain. 
A. Dysphagia, B. Swelling on posterior wall of pharynx, C. Toicollis, D. Caries of cervical spine is usually a common cause
D: Caries of cervical spine is usually a common cause
Answer: D: Caries of cervical spine is usually a common cause 
Explanation: CLINICAL FEATURES 1. Dysphagia and difficulty in breathing are prominent symptoms as the abscess obstructs the air and food passages. 2. Stridor and croupy cough may be present. 3. Toicollis. The neck becomes stiff and the head is kept extended. 4. The bulge in the posterior pharyngeal wall. Usually seen on one side of the midline. Radiograph of soft tissue, lateral view of the neck shows widening of preveebral shadow and possibly even the presence of gas (Ref: Diseases of ear, nose and throat, P.L Dhingra, 7th edition, page 300)