Convert active to passive: 'They cleaned the room.'

**The reasoning** In passive voice, the **object receives the action** and becomes the sentence's subject. Here's the transformation: **Active:** They (subject) cleaned (verb) the room (object) **Passive:** The room (new subject) + was cleaned (past tense "be" + past participle) + by them (agent) The principle: **Passive = Object + be (correct tense) + past participle + by + original subject** Since "cleaned" is past tense, we use "was" (past form of "be"). The room is singular, so "was" not "were." **Why the wrong options tempt you** **A)** "The room cleaned them" — This keeps active structure. The room can't perform the action of cleaning! **C)** "They was cleaned" — Wrong subject (should be "the room," not "they") plus wrong verb agreement ("they" takes "were," not "was"). **D)** "Cleaned the room they" — Just scrambled words with no proper passive structure. Sounds like Yoda! **Quick takeaway** For passive voice, flip it: make the object your new subject, add the right form of "be," use the past participle, then add "by" + the original doer. **Object + was/were + past participle + by + subject.**