Which two of the following compounds belong to the same homologous series?
$C_{2}H_{6}O, C_{2}H_{6}O_{2}, C_{2}H_{6}, CH_{4}O$

• A
  $C_{2}H_{6}O$ and $C_{2}H_{6}O_{2}$
• B
  $C_{2}H_{6}O$ and $CH_{4}O$
• C
  $C_{2}H_{6}$ and $CH_{4}O$
• D
  $C_{2}H_{6}O_{2}$ and $C_{2}H_{6}$