Answer: C. The fist the drill sergeant hides behind his back represents the power he has over the men.
A symbol is a mark, a sign, a word, a gesture, an idea or an image that is used to convey an idea or belief. Symbols create links between otherwise very different concepts and experiences. In this case, the best example of the use of a symbol is option C. The symbol in this sentence is the fist the drill sergeant has behind his back. Moreover, the sentence tells us that this is meant to represent the power that he has over men.
I'm assuming the underlined conjunctions are <em>both </em>and <em>and </em>(because you didn't underline any, and those are the only two conjunctions in the sentence).
Those conjunctions are called correlative conjunctions - this means that they are connecting two items which are equally important. So, this woman saw both Billie Holiday and Ella Fitzgerald - and both of those artists are important to the woman.
