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: Social & Preventive Medicine
[{'content': 'Commonest carcinoma in men in tropical countries- \nSelect and explain. \nA. Ca rectum, B. Ca oral cavity, C. Ca testis, D. Ca bladder', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most common cancer in males in India\xa0→ Oro-pharyngeal Ca (Aero-digestive Ca).\nMost common cancer in males in world → Lung Ca.\nMost common cancer in females in India\xa0→ Cervical cancer.\nMost common cancer in females in world\xa0→ Brast Ca.\nMost common overall cancer in the world (combined male & female) → Lung cancer.\nMost common cancer related death in males in India & in world\xa0→ Ca lung.\nMost common cancer related death in females in India & in world\xa0→ Breast cancer.', 'role': 'assistant'}]