Involuntary muscle contraction, such as those in the pupil of the eye, digestive tract, and diaphragm are the responsibility of the

a cerebrum
b medulla oblongata
c cerebellum
d spinal cord

Cerebrum controls the higher brain function such as speech, writing, etc. The cerebellum controls the involuntary stuff such as your digestive track, breathing, etc.  The other 2 control a branch of other stuff. C is your answer.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

what? are the statements?