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
Sleep waves in the hippocampal area are 
Select and explain. 
A. Delta, B. Theta, C. Beta, D. Alpha
B: Theta
Answer: B: Theta 
Explanation: Sleep waves and brain areas
-        Alpha rhythm- Parietal and occipital lobe
-        Beta rhythm- Frontal lobe
-        Theta rhythm- Hippocampus (Mammals other than human), Cortex (Human)