Greg purchased supplies for a party. He had a coupon good for 30% off. He purchased a helium tank rental with an original price of $31.61, a sheet cake with an original price of $18.44, a punch bowl with an original price of $12.78, and paper decorations with an original price of $23.69. Greg’s total came to $80.99. To which item did Greg apply his coupon?a.cakeb.helium tank rentalc.paper decorationsd.punch bowl