Which of the following reactions produce ethyl cyanide $(CH_3 CH_2 CN)$ as a major product?
$1.$ $CH_3 CH_2 CH=NOH \xrightarrow{(CH_3 CO)_2 O} CH_3 CH_2 CN$
$2.$ $CH_3 CH_2 Cl \xrightarrow{\text{Ethanolic } KCN} CH_3 CH_2 CN$
$3.$ $CH_3 CH_2 Cl \xrightarrow{\text{Ethanolic } AgCN} CH_3 CH_2 NC$
$4.$ $CH_3 CH_2 CON(CH_3)_2 \xrightarrow[\text{Pyridine, } 70^{\circ} C]{C_6 H_5 SO_2 Cl} CH_3 CH_2 CN$

• A
  $1, 2$
• B
  $2, 3$
• C
  $3, 4$
• D
  $1, 4$