The compound $A$ on treatment with $\text{Na}$ gives $B$, and with ${\text{PCl}}_5$ gives $C$. $B$ and $C$ react together to give diethyl ether. $A,B$ and $C$ are in the order:

1. A
   ${\text{C}}_2{\text{H}}_5\text{Cl},{\text{C}}_2{\text{H}}_6,{\text{C}}_2{\text{H}}_5\text{OH}$
2. B
   ${\text{C}}_2{\text{H}}_5\text{OH},{\text{C}}_2{\text{H}}_5\text{Cl},{\text{C}}_2{\text{H}}_5\text{ONa}$
3. C
   ${\text{C}}_2{\text{H}}_5\text{OH},{\text{C}}_2{\text{H}}_6,{\text{C}}_2{\text{H}}_5\text{Cl}$
4. D
   ${\text{C}}_2{\text{H}}_5\text{OH},{\text{C}}_2{\text{H}}_5\text{ONa},{\text{C}}_2{\text{H}}_5\text{Cl}$