3. Which of the following statement best describes the sodium pump (Na*-K+ ATPase)? (A) A major P-type transporter to adjust the imbalance of Nat and K+ concentration inside and outside the cell due to action potential (B) It pumps out 2 sodium ions in exchange of 3 potassium ions into the cytosol (C) The pump is a symporter (D) The operation of the pump is a Nat-dependent dephorsphorylation and K⁺-dependent phosphorylation