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': 'Investigation of choice for leptomeningeal carcinomatosis - \nSelect and explain. \nA. PET, B. SPECT, C. Gd enhanced MRI, D. CT scan', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]