Copper matte is a mixture of copper sulfide and iron sulfide formed as a result of smelting of copper ore. It contains mainly copper sulfide (Cu₂S) as the major component and iron sulfide (FeS) as a minor component.

The compounds A. CuCO₃, C. Cu₂O, and D. FeO are not present in copper matte, but can be formed as a result of further processing or refining of the matte.

Therefore, among the given compounds, only "B. Cu₂S" is present in copper matte.