A gas X is passed through water to form a saturated solution. The aqueous solution on treatement with `AgNO_(3)` gives a white precipitate. The saturated aqueous solution also dissolves Mg ribbon with evolution of colourless gas `Y,X` and Y are respectively:
A. `CO_(2)" and "Cl_(2)`
B. `Cl_(2) " and "CO_(2)`
C. `Cl_(2) " and "H_(2)`
D. `H_(2) " and " Cl_(2)`