Which rhetorical element is associated with the audience?

a.
ethos
b.
logos
c.
pathos
d.
syllogism

The correct answer is C. pathos.

Pathos refers to emotions, both those of the audience and of the speaker him/herself. What the audience is feeling when listening to a speech and the emotions that the speaker is trying to convey to the audience and elicit from the audience refers to pathos, the rhetorical element that has to do with feelings and attitudes. 
Ethos has to do with evidence and proof, and logos with logic.