Exposition is the part of the plot structure that introduces the charachters and setting.
C. Deena owed her brother $25.00.
Ms. Garcia was leading a tour of the gallery when the fire alarm sounded.
This is correct because it is the only sentence where the verbs match tenses.
Refute means to :
prove (a statement or theory) to be wrong or false; disprove.
prove that (someone) is wrong.
deny or contradict (a statement or accusation).
So, I'll go for...
O An opposing alternative way to view or interpret the topic
Or it could be
O An explanation that disproves something
Hope this helps!