81. Why does the pH value afiect the separation of amino acids by electrophoresis? Please choose tiie wrong reason. (A) Amino acids exist as zwitterions. (B) At low pH values, the amino acid molecules will be strongly attracted to the negative electrode. (C) At high pH values, the amino add molecules will be strongly attracted to the negative electrode. (D) In basic solution, the net chaise is negative due to die dissociation of the carboxylic acid groups. (E) None of the above.