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
The usual voltage of alpha rhythm is 
Select and explain. 
A. 5 mv, B. 10 mv, C. 50 mv, D. 100 mv
C: 50 mv
Answer: C: 50 mv 
Explanation: Alpha waves are neural oscillations in the frequency range of 8-12 Hz arising from the synchronous and coherent (in phase or constructive) electrical activity of thalamic pacemaker cells in humans. Ref: guyton and hall textbook of medical physiology 12 edition page number: 818,819,820