The correct option is C Copper carbonate
Copper gains a green coating of basic copper carbonate on its surface when exposed to the atmosphere due to its reaction with oxygen, carbon dioxide and moisture. The reactions that takes place are given below:
4Cu(s)+O2(g)→2Cu2O(s)
2Cu2O(s)+O2(g)→4CuO(s)
2CuO(s)+CO2(g)+H2O(l)→CuCO3(s)+Cu(OH)2(aq)