Reaction of Zn with different concentration of HNO3 are as follows: Zn+4HNO3(60%)⟶Zn(NO3)2+2NO2↑+2H2O 3Zn+8HNO3(30%)⟶3Zn(NO3)2+2NO↑+4H2O 4Zn+10HNO3(20%)⟶4Zn(NO3)2+N2O↑+5H2O 5Zn+12HNO3(10%)⟶5Zn(NO3)2+N2↑+6H2O 4Zn+10HNO3(3%)⟶4Zn(NO3)2+NH4NO3+3H2O Hence option (c) is correct.