What are A and B in the following reactions?
\(\mathrm{A} \xrightarrow{\mathrm{H}_2 / \mathrm{Ni}} \mathrm{RCH}_2 \mathrm{NH}_2 \xrightarrow[\text { ii) } \mathrm{H}_2 \mathrm{O}] {i) \mathrm{LiA} / \mathrm{H}_4} \mathrm{~B}\)

1. A \(\begin{array}{cc}
   \underline{\mathrm{A}} & \underline{\mathrm{B}} \\
   \mathrm{RCH}_2 \mathrm{NC} & \mathrm{RCH}=\mathrm{NOH}
   \end{array}\)
2. B \(\begin{array}{cc}
   \underline{\mathrm{A}} & \underline{\mathrm{B}} \\
   \mathrm{RCH}=\mathrm{NOH} & \mathrm{RCN} \\
   \end{array}\)
3. C \(\begin{array}{cc}
   \underline{\mathrm{A}} & \underline{\mathrm{B}} \\
   \mathrm{RCONH}_2 & \mathrm{RCH}_2 \mathrm{NC}
   \end{array}\)
4. D \(\begin{array}{cc}
   \underline{\mathrm{A}} & \underline{\mathrm{B}} \\
   \mathrm{RCN} & \mathrm{RCONH}_2
   \end{array}\)