Ninety-nine percent of the human body is composed of these six types of ______: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorous.

Responses:

a) sensors

b) cells

c) epithelial tissues

d) atoms

d) atoms

d) atoms

The correct answer is d) atoms. Ninety-nine percent of the human body is composed of atoms. In particular, the six types of atoms mentioned - oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus - are the most abundant elements found in the human body.