Read the following statements.

I) Photorespiration is favoured by high ${\mathrm{O}}_2$, low ${\mathrm{CO}}_2$, rise in temperature and high light intensity.

II) Chloroplast of bundle sheath cells of ${\mathrm{C}}_4$ plants, which are grana less and have RuBisCO.

III) Pure fats and proteins are never used as respiratory substrates.

IV) Glycerol enters respiratory pathway at DHAP form.

Choose the correct option.