Which of the following mixtures would give a black precipitate on passing `H_2 S` through its acidified aqueous solution?

Options

A. `Cu^(2+) and Pb^(2+)`
B. `Zn^(2+) and Mg^(2+)`
C. `Mg^(2+) and Fe^(2+)`
D. `Mg^(2+) and Ni^(2+)`

Answer

A

Explanation

`Cu^(2+) and Pb^(2+)`