Answer
do you need us to write the whole essay or just the main essay points
The correct sentence is: Two of the best singers were them. This makes sense because when you rephrase the sentence, "them" becomes "they" which appropriately describes the nouns of the sentence. The modified sentence then becomes: They were the best singers.
I would say probably B) The image of wild and lone.
Buuttt.. It could possibly be something different.. (Maybe C?)