Пасивный залог the rooms ... And looked tidy A. were cleaned B.cleaned C.were cleaning D.are cleaning

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".

The rooms A. were cleaned and looked tidy.