This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
[{'content': 'The sengstaken tube must be maintain a pressure of _______ to stop bleeding from varices \nSelect and explain. \nA. 20mmHg, B. 25mmHg, C. 35mmHg, D. 45mmHg', 'role': 'user'}, {'content': "Answer: C \nExplanation: If bleeding doesn't stop promptly, the gastric balloon may be inflated to atleast a volume of 300ml, or the esophageal balloon may be inflated to a pressure of 40mmHg Ref: Sabiston 20th edition Pgno : 1438", 'role': 'assistant'}]