The outcomes from tests carried out on three gases, X, Y and Z, are given below. Tests: - Aqueous potassium manganate(VII): X changes from purple to colourless; Y remains unchanged; Z remains unchanged. - Damp red litmus paper: X remains unchanged; Y changes to blue; Z remains unchanged. - Lighted splint: X remains unchanged; Y remains unchanged; Z makes a popping sound. What are X, Y and Z?
- AX: chlorine; Y: sulfur dioxide; Z: hydrogen
- BX: chlorine; Y: sulfur dioxide; Z: oxygen
- CX: sulfur dioxide; Y: ammonia; Z: oxygen
- DX: sulfur dioxide; Y: ammonia; Z: hydrogen