You observe every fall that the trees in the forest lose their leaves, but by the following fall, the leaves have disappeared. The most accurate explanation for this observation would be:

the trees died

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.