<prompt> A patient presenting with progressive dysphagia and in Barium shows bird-beak appearance. What is the Investigation of Choice?ManometrypH monitoringEndoscopyCECT scan  <response>: Ans. a ManometryRef: Sabiston 20th Edition, Page 1018 IOC for Achalasia Cardia is Manometry. Three types of Achalasia cardia are there as per Chicago Classification 