A recipe for making chocolate chip cookies calls for 2 1/2 cups of sugar for a dozen cookies (12). If you want to make 30 cookies, choose a proportion that would work to tell you how many cups of sugar you should use.
A: x/12 = 2.5/30
B: 2.5/12 = x/30
C: 2.5/30 = 12/x
D: 12/2.5 = x/30
