The correct option is D Chlorine
Deacon process is used for the manufacture of chlorine from the HCl. In this process, air is used to oxidise HCl in the presence of CuCl2 (catalyst) at 713 K.
4HCl+O2CuCl2⇌713 K2Cl2+2H2O.
Reaction is reversible and conversion is 65%.