Composition variable a, element
b. mixture
c. substance
d. compound
e. matter

c. Substance

Explanation:

A composition variable is an intensive property that indicates the relative amount of a particular species or substance in a phase.

is b the anwer is b

Explanation:

because mixture is a composition variable

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.

the volume increases