I believe the answer is: D.Measuring the rate of squirrel births in a woodland habitat
Biology comes from word "bios" which mean live and "logos" which mean study. Biology is science that study the living things. Star is not living things and it should be studied in astrology. Bank account also not living things, it should be studied in economy. Building also not living things, it should be studied in physics or engineering. Squirrel would be the only living things mentioned in the option.
Biology is the study of life. Environment includes the surroundings and the lives involved on it. Therefore, plastic affect both the surrounding and the lives of every living creature.
(c). Figuring out how pesticides affect plant growth
Biology can be defined as a branch of science, which includes study of living organisms, their chemical processes, physical structures, development, molecular interactions, and physiological mechanisms.
As in last option, effects of pesticides is tested in plants, which are living organisms, this activity would be within the field of biology.
Thus, the correct answer is option (C).
c. Figuring out how pesticides affect plant growth.
C.Doing research on how plastic affects the environment.
a. measuring the size of a star