The solution remaining from Part A, which contains 0.0100 MM Ni2+ Ni2+ and Fe2+Fe2+ ions, is still saturated with H2SH2S gas, producing a concentration of 0.100 MM. A buffer is added to this solution to produce a pH of 1.51 . Which of the following describes correctly the effect of the addition of the buffer? a) Only NiS precipitates. b) Only FeS precipitates. c) Both NiS and FeS precipitate. d) Neither NiS nor FeS precipitate.