Пасивный залог the rooms and looked tidy a. were cleaned b.cleaned c.were cleaning d.are cleaning

The rooms A. were cleaned and looked tidy.

The rooms were cleaned and looked tidy.

cleaned не может быть, т.к. в пассивном залоге всегда присутствует глагол "be" в любой форме.

were cleaning не может быть, т.к. в пассивном залоге Past Simple Progressive пишется "was/were+being+V3".

are cleaning не может быть, т.к. в пассивном залоге Present Simple Progressive пишется "am/is/are+being+V3".