The correct answer is D. Active transport
Active transport in the cells is a process of absorption of atoms or molecules against the concentration gradient. In order to do this, cells need to produce special kinds of transporters, called molecular pumps that facilitate the absorption of the atoms/molecules. During active transport the pumps spend energy gotten from the molecule of ATP.
In contrast, during the process of osmosis the molecules/atoms move with the concentration gradient and require no energy to do so.
