Most K⁺ is located in the cells,with little K⁺ in the tissue spaces.What accounts for the movement of additional K⁺ into the cells?

A) K⁺ in the tissue fluid diffuses into the cell.
B) K⁺ enters the cell in response to facilitated diffusion.
C) K⁺ is actively pumped into the cell.
D) K⁺ enters the cell because of pinocytosis.