The only type of microscope which requires no specimen prep is the…?

a. scanning electron scope
b. compound light scope
c. stereo ( dissecting) scope
d. transmission electron scope

Google defines it as:

"a region of the forebrain below the thalamus which coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, and involved in sleep and emotional activity."

basically, its a part of the brain below the thalamus and it controls your homeostatic systems. it also helps decide if you're gonna get good sleep and how you feel