Pumps are transporters that are able to harness energy provided by other components in the cells to drive the movement of solutes across membranes AGAINST their concentration gradient. This type of transport is called:
A. active transport
B. free diffusion
C. facilitated diffusion
D. passive transport

Explanation:

1. Active transport is the process of transport of molecules against the concentration gradient with the help of energy.

2. In active transport, a protein pump uses energy( in the form of ATP), and it  move molecules from region of low concentration to region of high concentration  across a membrane.  

3. Example of active transport:  The sodium-potassium pump,

The sodium-potassium pump  moves sodium ions out of the cell and potassium ions into the cell against their concentration gradient.