Correct Answer - B
(a) is used only to separate azerotrope, i.e., constant boiling mixture.
(b) is correct because `"CCl"_(4)` and acetone differ in their boiling point.
(c ) is used only in case of steam volatile substance. It is not correct.
(d) Vacuum distillation is used in liquids which decompose at their boiling point.
`:.` It is not correct.