be truthful to yourself and others be treated how you would want to be treated and don't lie and cheat
Expedient in this excerpt means for something to be appropriate to a purpose.
The answer would be C<span>. Music often takes away from a film’s believability and realism. Often time music is added to make the film believable and realistic, such as the creaking of a door or stairs without showing the actual scene. It also adds to the tone that the story is portraying.</span>