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: Surgery
[{'content': 'For early diagnosis of Ca stomach which method is used \nSelect and explain. \nA. Endoscopy, B. Staining with endoscopy biopsy, C. Physical examination, D. Ultrasound abdomen', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Endoscopy is the best method to diagnose gastric cancer as it visualizes the gastric mucosa and allows biopsy for a histological diagnosis Chromoendoscopy helps in identification of mucosal abnormalities through topical stains Magnification endoscopy is used to magnify standard endoscopic field by 1.5-150 times. Narrow band imaging affords increased visualisation of the microvasculature Confocal laser endoscopy permits in vivo, three dimensional microscopy including subsurface structures EUS is a tool for preoperative staging and selection for neo adjuvant therapy Ref: Sabiston 20th edition Pgno : 1218-1221', 'role': 'assistant'}]