Correct Answer: Where have you hidden those important documents?

Solution : The third option is correct.

The active voice is a type of sentence or clause in which the subject performs the action. It's a more direct and straightforward way of expressing ideas. In an active sentence, the subject is the doer of the action, and the object is the receiver of the action.

The structure of the sentence in active voice in an interrogative sentence is: "Wh word + have + subject + past participle form of the verb + object?"

Therefore, the correct answer is: " Where have you hidden those important documents? "