Tickets to a play normally cost $60. The cost is $45 if reserved early. If total ticket sales to a particular play were $2,400, which equation best models the number of normal tickets, x, and reserved tickets, y, sold?
A. 60x+45y=2400
B. 2400−(xy)=60−45
C. 105(x+y)=2400
D. x+y=2400