10. You find that the CEC of a sandy loam soil at pH 5.0 is 8 cmolc/kg and at pH 8.2 it is 14 cmolc/kg. What is the most likely reason for this difference? A increase in the pH-dependent charges on 1:1 type silicate clays B. removal of AlS+ ions from the exchange complex at higher pH. C. ionization of carboxyl and phenolic groups to release H ions D. removal of Al atoms from tetrahedral layers at low pH. E. replacement of trivalent A3+ ions with divalent Ca2 ions at high pb.