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
[{'content': 'Non progressive contraction of Esophagus are: \nSelect and explain. \nA. Primary, B. Secondary, C. Tertiary, D. Quaternary', 'role': 'user'}, {'content': 'Answer: C \nExplanation: • Tertiary contractions are simultaneous, non progressive, non peristaltic waves that can occur throughout the esophagus\n• Tertiary contractions represent uncoordinated contractions of the smooth muscles that are responsible for the ‘Cork Screw’ appearance of esophageal spasm on Barium swallow\n• Tertiary contractions do not have a physiological function and may be observed in the elderly and in patients with esophageal motility disorders', 'role': 'assistant'}]