David is selling floral arrangements. each arrangement uses 1 vase and 12 roses. each vase costs david $2.00. let c be the total cost of the arrangement and r be the cost of 1 rose. which equation should david use to find the total cost of each arrangement? a. c = 2r + 12 b. 12c = r + 12 c. 12 = c + 2r d. c = 12r + 2 5 points