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: Pharmacology
[{'content': 'Posterior column sensations in lower limbs are lost in : \nSelect and explain. \nA. Vitamin A deficiency, B. Vitamin B12 deficiency, C. Vitamin C deficiency, D. Vitamin D deficiency', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Deficiency of vitamin B12 leads to megaloblastic anemia which is indistinguishable from folic acid deficiency.\nDeficiency also have manifestations related to loss of myelin-like subacute combined degeneration of spinal cord (symptoms of lesions of a posterior column like loss of vibration and proprioception, paraesthesias, depressed stretch reflexes and mental changes like poor memory and hallucinations etc.)', 'role': 'assistant'}]