Human pupil size can change in response to light availability. This happens in each eye as the iris, which is the colored part of the eye, expands and contracts to regulate the amount of light entering each pupil.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

it marks things for degradation via the proteasome. it alters there celluar location.

c.           is the correct answer