In the above conversion of compound \( (X) \) to product \( (Y) \), the sequence of reagents to be used will be :
(i) \( \mathrm{Fe}, \mathrm{H}^+ \) (ii) \( \mathrm{Br}_2(\mathrm{aq}) \) (iii) \( \mathrm{HNO}_2 \) (iv) \( \mathrm{H}_3\mathrm{PO}_2 \)
(i) \( \mathrm{Br}_2, \mathrm{Fe} \) (ii) \( \mathrm{Fe}, \mathrm{H}^+ \) (iii) \( \mathrm{LiAlH}_4 \)
(i) \( \mathrm{Fe}, \mathrm{H}^+ \) (ii) \( \mathrm{Br}_2(\mathrm{aq}) \) (iii) \( \mathrm{HNO}_2 \) (iv) \( \mathrm{CuBr} \)
(i) \( \mathrm{Br}_2(\mathrm{aq}) \) (ii) \( \mathrm{LiAlH}_4 \) (iii) \( \mathrm{H}_3\mathrm{O}^+ \)