C-10-Q116mediumsingle_mcqRusting of iron requires—aboth O2\mathrm{O_2}O2 and H2O\mathrm{H_2O}H2Obonly O2\mathrm{O_2}O2conly H2O\mathrm{H_2O}H2Odonly CO2\mathrm{CO_2}CO2