胺基乙酸之梭基的Ka=4.3x10^(-3),胺基的Kb=6.0x10^(-3).若將少量胺基乙酸溶於ph=1.0的水溶液,則下列各結構之物種,何者濃度最大?
A H2N-CH2-COOH
B H3N+-CH2-COOH
C H3N+-CH2-COO-
D H2N-CH2-COO-