Casey's grandmother sent her an $80 bookstore gift card for her birthday last year. This year, she sent her a $110 bookstore gift card. Which proportion can be used to find the percent of last year's gift that this year's gift is, if n represents the unknown percent?
A 100/110 = 80/n
B 80/110 = n/100
C 110/80 = n/100
D 101/100 = 80/n