There are a number of properties that all organisms share. in humans, exposure to ultraviolet light can result in a darkening of the skin. what kind of property is this?
a. energy processing
b. response to the environment
c. regulation
d. growth and development

b. response to the environment

Explanation:

The ozone layer filters out most of the sun's harmful UV( ultraviolent) radiation. But when various environmental stresses and other human anthropogenic factors occurs, depletion of the ozone layer sets in and excessive production of Ultraviolent light emerges as well. Exposure to these ultraviolent light have the tendency and capability of causing damage to the skin cells which in turn cause wrinkles and darkening to the skin, damage to the melanin or sometimes skin cancer.

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.