A theta wave is a Type of ________.

A. Brain wave associated with critical thinking.

B. Low frequency, high amplitude brain wave.

C. Sleep-related brain waves called spindles.

D. Low frequency, low amplitude brain wave.

Answer:- C. Sleep-related brain waves called spindles.

Theta waves happen during REM sleep in nonhuman creatures, Stage 2 NREM sleep in humans, and the sleepy state previous to sleep onset in new babies, adolescents, and adults. The specific waves have been recorded in the trances and hypnosis.