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
TRUE statement about achalasia cardia is: 
Select and explain. 
A. 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
B: Loss of ganglion cells within the esophageal myenteric plexus
Answer: B: Loss of ganglion cells within the esophageal myenteric plexus 
Explanation: 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.