Which one of the following is a double-displacement reaction?
A.) 2Li (s) + ZnSO4 (aq) → Li2SO4 (aq) + Zn (s)
B.) HNO3 (aq) + KOH (aq) → H2O (l) + KNO3 (aq)
C.) Fe (s) + CuSO4 (aq) → FeSO4 (aq) + Cu (s)
D.) 2Cu (s) + O2 (g) → 2CuO (s)