Answer:
c. Muscle Cells
Explanation:
the muscle cells undergo mitosis so that our muscles can grow in proportion to our bones, height, and weight.
I'm assuming it would be Population Density. My class never covered this subject greatly, but the definition is "Population density is a measurement of population per unit area or unit volume;" which sounds like what you are looking for.
Hope this helps!
-Payshence
The iris controls the amount of light that enters the eye by opening and closing the pupil. The iris uses muscles to change the size of the pupil. These muscles can control the amount of light entering the eye by making the pupil larger (dilated) or smaller (constricted).