In qualitative analysis `NH_4 Cl` is added before `NH_4 OH`

Options

A. The dissociation of `NH_(4)OH` increases
B. The concentration of `OH^(-)` increases
C. The concentration of both `OH^(-)` and `NH_(4)^(+)` increases
D. The concentration of `OH^(-)` decreases

Explanation

The concentration `OH^(-)` decreases due to common to effect.