Establishing a H⁺ Concentration Gradient Across the Cell Membrane

Establishing a H⁺ concentration gradient across the cell membrane

A) enables K⁺ ions to enter the cell via active transport.
B) prevents Cl⁺ ions from entering the cell.
C) enables certain cations to enter the cell moving against their concentration gradient.
D) facilitates the flow of water into the cell.
E) is important for reducing the acidity level within the cells.