This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sympathetic System, Subject name: Pharmacology
[{'content': 'A patient presented with history of few episodes of vomiting and was given an anti-emetic drug by the intern. Few hours later, the patient developed an abnormal posture. Which of the following is likely drug administered to him ? \nSelect and explain. \nA. Metoclopramide, B. Ondansetron, C. Domperidone, D. Dexamethasone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The abnormal posture is likely to be muscular dystonia. Metoclopramide can result in dystonias due to its D2 receptor blocking propey in the CNS. Domperidone also blocks D2 receptors but does not cross the blood brain barrier.', 'role': 'assistant'}]