$PbS$ can be separated from $ZnS$ by electrostatic separation. Which property is involved in this method?

• A
  $PbS$ is a conductor of electricity and $ZnS$ is an insulator.
• B
  $PbS$ is an insulator and $ZnS$ is a conductor of electricity.
• C
  Both $PbS$ and $ZnS$ are conductors of electricity.
• D
  Both $PbS$ and $ZnS$ are insulators.