Laurie's new student credit card has a 0% introductory apr for six months. the minimum payment per month for the card is $20. after the introductory period the apr is 15%. laurie buys a few presents using her credit card so that her total balance is $135. if laurie decides to make just the minimum payment, what would her balance be when the introductory period ends? select the best answer from the choices provided. a. $15 b. $35 c. $25.12 d. $21.63