Sergei has a credit card that uses the average daily balance method For the first 12 days of one of his billing cycles his balance was 350 and for the last 18 days of the billing cycle his balance was 520 If his credit card s APR is 14 which of these expressions could be used to calculate the amount Sergei was charged in interest for the billing cycle O A O B O C 0 14 365 0 14 365 0 14 365 30 0 31 12 350 18 520 30 31 18 350 12 520 31 12 350 18 520 31