This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oncology, Subject name: Medicine
[{'content': 'Commonest cancer in which metastasis is seen in the brain is - \nSelect and explain. \nA. Breast, B. Lung, C. Kidney, D. Intestines', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lung cancer(commonest metastasis to brain) and melanomas are most likely to present with multiple metastasis, whereas breast, colon, and renal cancers are more likely to present with a single metastasis. Ref Harrison 20th edition pg 539', 'role': 'assistant'}]