Consider the all-units quantity discount schedule below. Which of the following sets of order quantities is guaranteed to contain the optimal solution (i.e., best order quantity)? A. {986,1000,1500,2000} B. {1,500,1000,1500,2000} C. {986,1023,1500} D. {952,986,1023,1087,1166} E. {1023,1500,2000}