A balck powder when heated with Conc. HCI gives a greenish yellow. Gas. The gas as an oxidising and bleaching agent. When it is passed over slake lime, a white poweder is formed which is a ready source of gas. The back powder and white powder respectively are
A. `KClO_3` and `NaClO_3`
B. `MnO_2` and `Ca(O Cl)_2`
C. `MnO_2` and KClO
D. `MnCl_4` and `COCl_2`