Answer:
Primary active transport
Explanation:
Active transport may be defined as the movement of particles against their concentration gradient with the help of an energy source like ATP. Two main types of active transport are secondary active transport and primary active transport.
Primary active transport includes the sodium potassium pump because it directly uses the stored chemical energy in the form of ATP. Three sodium moves out of the cell and two potassium moves inside the cell with the help of ATP.
Thus, the correct answer is option (a).
