46. Which of the following description for Polymerase Chain Reaction is not true? (A) The length of the primers controls amplification specificity. (B) The Tm of the primers controls amplification specificity. (C) High Mg2+ concentration in the reaction increases the amplification specificity. (D) The Klenow fragment of DNA polymerase I retains the 5'→3' polymerase activity and the 3'→5' exonuclease activity. (E) The Klenow fragment of DNA polymerase I loses its 5'→3' exonuclease activity.