I'd go with A. can interact to influence a trait, such as eye color
Answer:
A. It's a reliable source because it's from the government, not a website based on other people's opinions.
"The rotating part of the microscope at the bottom of the body tube; it holds the objectives." -utahscience.oremjr.alpine.k12.ut.us
B. Because the environment can not supply for the food and caring of the animal species that is growing larger.
