The National Honor Society is selling tickets for the spring dance. Tickets are $12 for couples and $8 for singles. Let x be the number of couples and y be the number of singles. This system of equations represents the situation in which ticket sales totaled $1,580 and a total of 250 students attended the dance. 12x + 8y = 1,580 2x + y = 250 How many singles tickets were sold? A)15 B)40 C)105 D)133