Which statement correctly describes the human muscular system
a. muscles of the body can pull and push
b. skeletal muscles often form in hollow internal structures
c. the smooth and cardiac muscles operate involuntarily
d. each bone is attached to one muscle

The correct answer would be C.The Smooth and cardiac muscles operate involuntarily

protein makes up the building blocks of organs, muscles, skin, hormones and pretty much everything that matters in your body.

some choices are:

peanut butter

seeds

eggs

yogurt

meats

fish

so pretty much meat, dairy, nuts, and grains.