Answer:
A. Move substances down a concentration gradient
Explanation:
Active transport is the process of transport of substances in an energy dependent manner. The process of active transport requires energy to transport the substances against their concentration gradient. This means that active transport moves the substances from the region of their lower concentration to that of higher concentration.
Answer: Commensalism
Explanation: Well you can already eliminate parasitism because that is when an organism leeches off another. Mutualism is when one organism needs to depend on another compared to A where both are benefited. Then you can eliminate d because competition is when two organism compete with each other for survival not benefiting them both.
