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: Surgery
Non progressive contraction of Esophagus are: 
Select and explain. 
A. Primary, B. Secondary, C. Tertiary, D. Quaternary
C: Tertiary
Answer: C: Tertiary 
Explanation: • Tertiary contractions are simultaneous, non progressive, non peristaltic waves that can occur throughout the esophagus
• Tertiary contractions represent uncoordinated contractions of the smooth muscles that are responsible for the ‘Cork Screw’ appearance of esophageal spasm on Barium swallow
• Tertiary contractions do not have a physiological function and may be observed in the elderly and in patients with esophageal motility disorders