Answer:
Group A is correct.
Step-by-step explanation:
3 sets($3/set) = $9 - $2 coupon = $7
9 sets($3/set) = $27 - $2 coupon = $25
12 sets($3/set) = $36 - $2 coupon = $34
24 sets($3/set) = $72 - $2 coupon = $70
none of the other groups fit this pattern.
