This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'In a chronic smoker, a highly malignant aggressive and metastatic lung carcinoma is : \nSelect and explain. \nA. Squamous cell Carcinoma, B. Adenocarcinoma, C. Large cell carcinoma, D. Small cell Carcinoma', 'role': 'user'}, {'content': "Answer: D \nExplanation: Cigarette smoking is most strongly associated with squamous Cell Ca and small cell Ca and less commonly associated with Adenocarcinoma.\nBut small cell Ca is highly malignant & Blood stream metastasis occurs early in the course of this Ca.So the answer is small cell carcinoma.\xa0\nAlso Remember\nM.C Variety of lung Ca in India → Squamous Cell Ca*\nM.C Variety in world → Adenocarcinoma*\nM.C Variety in young Patients → Adenocarcinoma*\nHistological Variety that cavitates → Squamous cell Ca*\nM.C Histological variety to metastasi → Small cell Ca*\xa0\nLung to lung metastasis is seen in → Bronchoalveolar Ca (a type of adeno Ca)\nClubbing least common in which Ca → Small cell Ca*\nGynaecomastia is seen in which type of Ca → large Cell Ca*\nThrombophlebitis is seen with which Ca → Adenocarcinoma*\nMost common site for metastasis from ca lung → Adrenals* (Ref Robbins Basis 7/e, p 760)\nLung Ca with worst prognosis → Small cell Ca*\xa0\nVariety most responsive to chemotherapy → Small cell Ca*\nVariety most responsive to radiotherapy → Small cell Ca*\nM.C Endocrine Gland to be involved by metastasis → Adrenal*\nVariety with best prognosis → Squamous cell CA*\nVariety that is central in location → Squamous cell & small cell Ca*\nVariety that is peripheral in location → Adenocarcinoma*\nMost common variety with Cushing's syndrome → Small cell Ca*\nMost common variety with Hypercalcemia → d/t PTH like substance Secretion → Squamous cell Ca*", 'role': 'assistant'}]