What is or are the principal element(s), apart from carbon and hydrogen, in mustard gas?

Question

APhosphorus and fluorine

BChlorine and fluorine

CSulphur and chlorine

DArsenic and chlorine

Select from the options above.

Correct Option: 3  

Explanation:
The chemical term for mustard gas is bis(2-chloroethyl) sulfide. The gas causes blisters on the skin, eyes and throat.