Which of the following is an example of secondary active transport using an antiporter?
A: A transporter that allows mammalian cells to move biotin into the cell against its concentration gradient using the Na+ gradient.
B: A transporter that moves HCO3- out of erythrocytes and Cl- into erythrocytes in actively respiring tissues but reverses the direction of solute movement in lungs.
C: A transporter in the plasma membrane of mammalian cells that uses ATP hydrolysis to move Na+ and K+ against their concentration gradients.
D: A transporter that allows mammalian cells to keep the cytosolic Ca2+ concentration low compared to the extracellular Ca2+ using energy from the Na+ gradient.