What Is the Composition of the Precipitate Formed When H₂S

Multiple Choice

What is the composition of the precipitate formed when H₂S gas is bubbled through 1.0 litre of a solution of 0.010 M Zn²⁺,0.010 M Pb²⁺,and 0.010 M Mn²⁺,buffered at pH 2.0,until 0.10 mol of H₂S has been added?
(K_sp values are: ZnS: 1.6 × 10^-23;MnS: 7.0 × 10^-16;PbS: 7.0 × 10^-29.For H₂S,K_a1 = 1.0 × 10^-7;K_a2 = 1.3 × 10^{-13 )} .

A) only ZnS
B) only MnS
C) only PbS
D) only MnS and PbS
E) only ZnS and PbS