SORRY I DON'T KNOW
MAYBE I CAN HELP YOU OTHER WAY OUT
sorry for my bad handwriting lol-
Answer:
A. The atria are contracting and pushing blood into the bottom ventricles of the heart.
mark me brainliyeast
It should be 2, pituitary gland. (: It's referred as the master gland.
I hope all is well, and you pass. Good luck, rockstar!