In the following questions, two or more options may be correct. Some oxidation reactions of methane are given below. Which of them is/are controlled oxidation reactions? (i) CH4 (g) + 2O2 (g)→ CO2 (g) + 2H2O (l) (ii) CH4 (g) + O2 (g) → C (s) + 2H2O (l) (iii) CH4 (g) + O2 (g) →(Mo O2 3) HCHO + H2O (iv) 2CH4 (g) + O2 (g) → (Cu/523/100 atm) 2CH3OH