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: Medicine
[{'content': 'TRUE statement about achalasia cardia is: \nSelect and explain. \nA. Achalasia is a common disorder, B. Loss of ganglion cells within the esophageal myenteric plexus, C. Excess LES relaxation is the major pathology, D. Latent infection with rubella virus is responsible for it', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Achalasia is a rare disease It is caused by loss of the ganglion cells within the esophageal myenteric plexus With long-standing disease, viual aganglionosis is noted. Pathology: Impaired deglutitive LES relaxation and absent peristalsis. It is believed that cause of ganglion cell degeneration in achalasia is an autoimmune process attributable to a latent infection with human herpes simplex virus 1 combined with genetic susceptibility. Ref: Harrison, Edition-18, Page-2431.', 'role': 'assistant'}]