This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Clinical Presentation and Physiology, Subject name: Surgery
[{'content': 'Commonest site of Ca breast is: \nSelect and explain. \nA. Upper outer quadrant, B. Upper inner quadrant, C. Lower outer quadrant, D. Lower inner quadrant', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans: a (Upper outer quadrant) Ref: Bailey & Love, 24th ed, p. 837Note:Breast carcinoma with good prognosis evenwith axillary lymph nodes-Medullary CaBull\'s eye appearance is seen in- Invasive lobularDesmoplastic reaction is shown by- Ductal invasiveComedo carcinoma is- Ductal carcinoma in situ (DCIS)Most common variant of breast carcinoma- Ductal invasiveLobular carcinoma - Multicentnc and bilateralThe underlying lobular architecture can still be recognized on microscopic examination "Indian file pattern" is seen.', 'role': 'assistant'}]