A saturated solution of calcium hydroxide, Ca(OH)_2, is in contact with excess solid Ca(OH)_2. Which of the following statements correctly describes what will happen when aqueous HCl (a strong acid) is added to this mixture, and system returns to equilibrium? (For Ca(OH)_2, K_sp = 6.5 times 10^-6) A) The OH^- concentration will increase and the Ca^2+ concentration will decrease. B) The solubility of Ca(OH)_2 will be unchanged. C) The concentrations of both Ca^2+ and OH^- will increase. D) The solubility of Ca(OH)_2 will decrease. E) The OH^- concentration will decrease and the Ca^2+ concentration will increase.