The correct option is C Cu+2
Benedict's solution is used to test for aldehyde group. The aldehyde group oxidised and in the process, reduces the Cu2+ found in the complex provide by Benedict solution to form copper (I) oxide, Cu2O.
RCHO+Cu(citrate)2−2+5OH−→RCOO− + Cu2O↓ + 3H2OAldehyde Fehling's solution Carboxylate ion Brick Red ppt
Thus the correct option is (c).