Which of the Following Statements About the Na⁺-K⁺ Pump Is

Multiple Choice

Which of the following statements about the Na⁺-K⁺ pump is correct?

A) Phosphorylation of the pump must occur before Na⁺ can attach to its binding site.
B) It has ATP synthase activity.
C) It helps decrease Na⁺ and K⁺ concentration gradients across the plasma membrane.
D) It regulates cell volume by controlling the concentration of solutes inside the cell.
E) It is a countertransporter for secondary active transport.