This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous System, Subject name: Pathology
[{'content': 'Most common cause of brain metastasis is? \nSelect and explain. \nA. Carcinoma lung, B. Prostate cancer, C. HCC, D. Seminoma', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Carcinoma lung * Metastasis to brain are the most common brain tumor. Most common primary malignancy metastatizing to brain is lung carcinoma, followed by (in decreasing order of frequency) breast, skin (melanoma), kidney (genitourinary) and GIT cancers.* Prostate carcinoma, ovarian carcinoma and Hodgkin's disease are very unlikely to metastatize to brain.", 'role': 'assistant'}]