Which one of the following is the correct order of reagents to be used to convent [A] to [X]?
Reagents: \(\mathrm{PCC}, \mathrm{PCl}_{5}, \mathrm{LiAlH}_{4}, \frac{\mathrm{KCN}}{\mathrm{H}_{3} \mathrm{O}^{+}}\)
1
\(\frac{K C N}{H_{3} \mathrm{O}^{+}} \quad \mathrm{PCl}_{5} \quad \mathrm{PCC} \quad \mathrm{LiAlH}_{4}\)
2
\(\begin{array}{llll} \mathrm{PCl}_{5}, & \frac{K C N}{H_{3} \mathrm{O}^{+}} & \mathrm{LiAlH}_{4} & \mathrm{PCC}^{-} \end{array}\)
3
\(\mathrm{LiAlH}_{4}, \frac{K C N}{H_{3} \mathrm{O}^{+}} \quad \mathrm{PCl}_{5} \quad \mathrm{PCC}\)
4
\(\begin{array}{lllll} \mathrm{PCC}_{C} & \mathrm{PCl}_{5} & \frac{K C N}{\mathrm{H}_{3} \mathrm{O}^{+}} & \mathrm{LiAlH}_{4} \end{array}\)