In the Proximal Tubule, Hydrogen Ions Are Transported into the Filtrate

Multiple Choice

In the proximal tubule, hydrogen ions are transported into the filtrate by

A) Na⁺/H⁺countertransporters only.
B) H⁺ primary active transporters only.
C) H⁺/Cl ^- cotransporters only.
D) both Na⁺/H⁺ countertransporters and H⁺ primary active transporters.
E) both Na⁺/H⁺ countertransporters and H⁺/Cl ^-cotransporters.