Which Statement About the Relative Concentrations of Na⁺ and K⁺

Which statement about the relative concentrations of Na⁺ and K⁺ inside and outside of a typical mammalian cell is true?

A) The concentration of Na⁺ and K⁺ outside the cell is about 30 times higher than inside the cell.
B) The concentration of Na⁺ outside the cell is about 30 times higher than inside the cell, and the concentration of K⁺ inside the cell is 10 to 30 times higher than outside the cell.
C) The concentration is the same for both ions, but there is a Cl^- ion concentration gradient across the plasma membrane.
D) The concentration of Na⁺ inside the cell is 30 times higher than outside the cell, and the concentration of K⁺ outside the cell is 10 times higher than inside the cell.