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': 'In CA stomach, T4 lesion means \nSelect and explain. \nA. Involved till serosa, B. Involved till lamnia propria, C. Involved till submucosa, D. Involved till muscularis propria', 'role': 'user'}, {'content': 'Answer: A \nExplanation: T1a Tumour involves lamina propria T1b Tumour involvessubmucosaT2 Tumour invades muscularis propriaT3 Tumour involves subserosa T4a Tumour perforates serosaT4b Tumour invades adjacent organsBailey and love 27e pg: 1135', 'role': 'assistant'}]