13: the table below relates the number of school lunches that you purchase and the amount of money (in dollars) that you have remaining on your school lunch card. cost of school lunch number of lunches purchased lunch card balance 0 $30.00 5 $15.00 9 $3.00 10 $0.00 the cost of school lunch is a linear function. select the best choice with regard to the rate of change. a the card balance decreases $3.00 each time 1 lunch is purchased. b the card balance decreases $12.00 each time 5 lunches are purchased. c the card balance increases $3.00 each time 1 lunch is purchased. d the card balance decreases $15.00 each time 1 lunch is purchased.