The correct option is C NH4Cl+NH4OH+H2S
The group reagent for Mn2+,Co2+,Zn2+,Ni2+ is NH4Cl+NH4OH+H2S as this belongs to fourth group
The fourth group of cations include
Mn2+,Co2+,Zn2+,Ni2+.
Of these, Zinc salts are colourless, Manganese salts are faint pink or colourless, and Nickel and cobalt salts may be brightly coloured, often blue-green.
The precipitate, washed in water is reacted with extremely dilute hydrochloric acid. This precipitates nickel salts if any.
The supernatant liquid is filtered and reacted with an excess of Sodium Hydroxide. This precipitates any Manganese salts.
Hydrogen sulphide is passed through the suppernatant liquid. If a white precipitate forms, Zinc is present.