Hot concentrated sulphuric acid is a moderately strong oxidizing agent. Which of the following reactions does not show oxidizing behaviour?
(a) Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O
(b) S + 2H2SO4 → SO2 + 2H2O
(c) C + 2H2SO4 → CO2 + 2SO2 + 2H2O
(d) CaF2 + 2H2SO4 → CaSO4 + 2HF