The correct sequence of reagents for the preparation of Q and R is:

Options

1. A(i) ${Cr}_{2}{O}_{3}, 770K, 20atm$; (ii) ${CrO}_{2}{Cl}_{2}, {H}_{3}{O}^{+}$; (iii) $NaOH$; (iv) ${H}_{3}{O}^{+}$
2. B(i) ${CrO}_{2}{Cl}_{2}, {H}_{3}{O}^{+}$; (ii) ${Cr}_{2}{O}_{3}, 770K, 20atm$; (iii) $NaOH$; (iv) ${H}_{3}{O}^{+}$
3. C(i) ${KMnO}_{4}, {OH}^{-}$; (ii) ${Mo}_{2}{O}_{3}, \Delta$; (iii) $NaOH$; (iv) ${H}_{3}{O}^{+}$
4. D(i) ${Mo}_{2}{O}_{3}, \Delta$; (ii) ${CrO}_{2}{Cl}_{2}, {H}_{3}{O}^{+}$; (iii) $NaOH$; (iv) ${H}_{3}{O}^{+}$