This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Physiology
Which one of the following statements about EEG is true? 
Select and explain. 
A. Alpha rhythm is most marked at parieto-occipital area, B. Beta rhythm is most marked at region below mastoid, C. In REM sleep, patient is awake, D. EPSP and IPSP of the cortical cells acting as dipoles
A: Alpha rhythm is most marked at parieto-occipital area
Answer: A: Alpha rhythm is most marked at parieto-occipital area 
Explanation: (A) Alpha rhythm is most marked at parieto-occipital area # Alpha Rhythm > In adult humans who are awake but at rest with the mind wandering and the eyes closed, the most prominent component of the EEG is fairly regular pattern of waves at a frequency of 8-12 Hz and an amplitude of 50-100 uV when recorded from the scalp.> This pattern is the alpha rhythm.> It is most marked in the parieto-occipital area, though it is sometimes observed in other locations.> A similar rhythm has been observed in a wide variety of mammalian species.> In the cat it is slightly more rapid than in the human, and there are other minor variations from species to species, but in all mammals the pattern is remarkably similar