Answer:
The correct answer is option b. "Alpha eventually replaced by theta".
Explanation:
Electroencephalogram (EEG) techniques allows researchers to monitor the phases of sleeping according of what brain waves are seen in the equipment. A normal adult connected to EEG will respond with alpha waves during a wakeful state. However, as the person becomes drowsy and enters to the first stage of sleep, the alpha waves will be eventually replaced by theta waves. Theta waves are the dominant waves during sleeping, and also could be seen during deep meditation.
The hydrogen molecules in water keep it together
