The total cost of gasoline varies directly with the number of gallons purchased. Edie pays $22.68 for 12
gallons of gasoline. Which equation shows the relationship between the total cost of gasoline, c, and the
number of gallons purchased, n?

A. c = 1.89n
B. n = 22.68c
C. c = 22.68n
D. n = 1.89c