A.
λ m (H + )/[λ m (H + ) + λ m (Ba 2+ ) + 2λ m (Cl - )]
B.
c 1 λ m (H + )/[c 1 λ m (H + )+ 2c 2 λ m (½ Ba 2+ )+ (c 1 + 2c 2 )λ m (Cl - )]
C.
c 1 λ m (H + )/[c 1 λ m (H + ) + c 2 λ m (Ba 2+ ) + λ m (Cl - )]
D.
c 1 λ m (H + )/[c 1 λ m (H + ) + 2c 2 λ m (Ba 2+ ) + 2c 2 λ m (Cl - )]