(A) `:` CdS and `As_(2)S_(3)` both have yellow colour and precipitated by passing `H_(2)S` through solution in dil HCl.
® `:` Both can be separated by yellow ammonium sulphide.

Answer

2

Explanation

`Cd^(2+)` belongs to group IIA
`As^(3+)` belongs to group IIB