the answer is
Ambifuos reference.
It is not clear that the <em><u>it </u></em>as a pronoun reference refers to the fact of singing higher or being different from others.
1. Mercenary
2. Bastion
3. Bacchanalian
4. Furtive
5. Extradite/extraditing
6. Copious
7. Avarice
"C" Seems like the most likely answer, it's a metaphor.
