Which of the following is incorrect statement?
A. If `K_(1)` and `K_(2)` for dissociation of `H_(2)A` is `10^(-7)` and `10^(-14)` then `A^(2-)` concentration in `0.1M H_(2)A` solution is `10^(-7)`
B. A solution of pH=1 has `H^(+)` ion concentration 3 times that of a solution of pH=3
C. If a salt solution of weak acid and weak base is dilute upto limited extent then its pH will decreases
D. pH of acidic bufer solution depends upon `pK_(a)` and relative molar amount of weak acid and its conjugate base.