If you think about it, this is what has happened to Ozymandias. He was so powerful in his day, but now his statues have fallen and no one knows his name. What was once his empire is now a backwater -- an "antique land." Everything that he worked for and accomplished has been forgotten -- his efforts were pointless.
The poem is implying that all of human life is like that. Nothing we do will last... the answer is "A. The past is irrelevant"
I hope this is the answer
