Answer: The correct answer is BOUNDLESS AND BARE. Trust me, I've just got 100% on the test.
Explanation: This supports the irony of the poem because the once boastful king who would say, "My name is Ozymandias, king of kings:
Look on my works, ye Mighty, and despair!" has now no audience to look upon his work. (I don't know if that made much sense XD )