Which is made up of only one type of atom? A. a solution
B. a homogeneous mixture
C. an element
D. a compound

C. an element

Explanation:

Elements are pure substances and made up of only one type of atoms which cannot be further broken down.

smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. those muscles push materials like food or blood through organs. unlike skeletal muscle, smooth muscle can never be under your control.