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: Anaesthesia
[{'content': 'In general, the last muscle to be rendered akinetic with a retrobulbar anesthetic block is – \nSelect and explain. \nA. Superior rectus, B. Superior oblique, C. Inferior oblique, D. Levator palpebral superioris', 'role': 'user'}, {'content': 'Answer: B \nExplanation: A properly placed retrobulbar injection is effective within seconds and blocks all extraocular muscles except the superior oblique muscle, affects the ciliary ganglion and anesthetizes the entire globe.', 'role': 'assistant'}]