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': 'Buerger waves (alpha waves) of EEG have the rhythm per sec of \nSelect and explain. \nA. 0-4, B. 7-Apr, C. 13-Aug, D. 13-30', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Stages of sleep and rhythm\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Beta rhythm- Alert, awake, maximum concentration- 13-30Hz\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Alpha rhythm- Eyes closed, mind wandering, less attentiveness- 8-13Hz\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Theta rhythm- Stage 1 NREM- 4-7 Hz\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Sleep spindles, K complex- Stage 2 NREM\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Delta rhythm- Deep sleep (Stage 3 & 4 NREM)- 3-5 Hz\n-\xa0\xa0\xa0\xa0\xa0\xa0\xa0 Beta Rhythm and occasional alpha rhythm- REM', 'role': 'assistant'}]