Two stores sell CDs in packages, as shown in the table below. CD Prices at Store A
Number of CDs in Package
1
12
20
45
Cost
$0.70
$8.40
?
$31.50

CD Prices at Store B
Number of CDs in Package
1
20
30
65
Cost
$0.60
?
$18.00
$39.00

If the rate at each store is constant, which statement correctly compares the cost of a package containing 20 CDs?