Suppose your school plans a musical. The directors goal is ticket sales of at least $4500. Adult tickets are $7.50 and student tickets are $5.00. Let a represent of adult tickets and a represents the number of student tickets. Which inequality represents the director's goal?

A)5a+7.5s<4500

B)7.5+5s>4500

C)7.5+5s<_(less or equal)4500

D)7.5a+5s>_(greater or equal)4500