The dimensions of $emf$ in $MKS$ system (in terms of charge $Q$) is:

• A
  $M{L^{ - 1}}{T^{ - 2}}{Q^{ - 2}}$
• B
  $M{L^2}{T^{ - 2}}{Q^{ - 2}}$
• C
  $ML{T^{ - 2}}{Q^{ - 1}}$
• D
  $M{L^2}{T^{ - 2}}{Q^{ - 1}}$