Which pair represents chain isomers?

• A
  $CH_3CHCl_2$ and $ClCH_2CH_2Cl$
• B
  $n$-propyl alcohol and isopropyl alcohol
• C
  $2$-methyl-$1$-propanol and $2$-methyl-$2$-propanol
• D
  $2$-methylbutane and neopentane