A store sells 12-packs of ballpoint pens for $1.09 each and composition books for $2.79 each. Cindy buys m packs of ballpoint pens and n composition books. The store offers a 5% discount for every 50th customer who makes a purchase. If Cindy gets the 5% discount, which expression will represent Cindy’s bill?
A.
0.05 − 1.09m + 2.79n
B.
1.05 + 1.09m + 2.79n
C.
1.05(1.09m + 2.79n)
D.
0.95(1.09m + 2.79n)