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: Physiology
[{'content': 'Involuntary contraction of a single motor unit is known as \nSelect and explain. \nA. Fibrillation, B. Fasciculation, C. Tics, D. Spasm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Fasciculation : It is involuntary contraction of a single motor unit. It is visible grossly.\nFibrillation\xa0: It is spontaneous, repititive contraction of a single muscle fibre. It is not visible grossly.', 'role': 'assistant'}]