Correct Answer: The hole was covered by the king with a huge stone.

Solution : The second option is the correct answer.

Passive voice is a grammatical construction where the subject of the sentence undergoes the action rather than performing it. The given sentence is an example of the active voice in simple past tense.

The structure of the passive sentence in the simple past tense is, object + was + past participle form of the main verb + by + agent of action + prepositional phrase.

Therefore, the correct answer is: "The hole was covered by the king with a huge stone."