Which of these is a pure substance that cannot be broken down by a chemical reaction?
O a neutron
O a compound
O an element
O a mixture

an element

Explanation:

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.