This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle, Subject name: Physiology
[{'content': 'Which receptors are blocked in Myasthenia Gravis? \nSelect and explain. \nA. Ach receptor, B. Ca++ receptors, C. Na+ receptors, D. Opioid receptors', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Auto-antibodies destroy some of the Nicotinic acetylcholine receptors and bind others to neighbouring receptors, triggering their removal by endocytosis.', 'role': 'assistant'}]