Blood Is Closely Maintained at a PH of 7

Blood is closely maintained at a pH of 7.4.A patient whose blood pH drops below 7.35 is suffering from metabolic acidosis and can go into a coma.What happens to the concentration of H⁺ ions in a patient with a blood pH of 6.4?

A) H⁺ concentration is decreased 10-fold.
B) H⁺ concentration is decreased 2-fold.
C) H⁺ concentration is increased 2-fold.
D) H⁺ concentration is decreased 4-fold.
E) H⁺ concentration is increased 10-fold.