PLEASE HELP!

Ziven is shopping at a back to school sale.

Which purchase shows financial responsibility?
A.
Buying two $20 shirts, each on sale for 50% off.

B.
Buying two $20 shirts at regular price and applying a $10 coupon.

C.
A $20 shirt bought at full price, and a second shirt with a 75% discount.

D.
Buying two $20 shirts, one with a 20% discount, and the other with a 30% discount.