The correct option is B Copper carbonate
When exposed to the atmosphere, copper reacts with oxygen and forms copper oxide. The reaction occurs as follows:
2Cu (s)+O2 (g)→2CuO (s)
This on reaction with carbon dioxide and water forms a greenish layer of basic copper carbonate. The reaction occurs as follows:
2CuO (s)+H2O(l)+CO2(g)→CuCO3(s)+Cu(OH)2(s)