This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Muscle relaxants, Subject name: Anaesthesia
[{'content': 'What is the time gap given in train of 4 \nSelect and explain. \nA. 10 Sec, B. 20 Sec, C. 40 Sec, D. None', 'role': 'user'}, {'content': 'Answer: D \nExplanation: In Train of four, four successive stimuli of 0.2sec are applied over 2sec,between two stimuli, the gap is 0.5sec as 4stimuli are applied at a constant interval in 2sec.', 'role': 'assistant'}]