18. Which element is oxidized in this balanced reaction and how does its oxidation numberchange? \mathrm{CH}_{4}+2 \mathrm{O}_{2} \rightarrow \mathrm{CO}_{2}+2 \mathrm{H}_{2} \mathrm{O} a) Carbon; it goes from -4 on the left

and 0 on the right b) Carbon; it goes from -4 on the left to +4 on the right c) Hydrogen; it goes from 0 on the left to +1 on the right d) Oxygen; it goes from 0 on the left to -2 on the right e) Oxygen; it goes from 0 on the left to +2 on the right