Timothy goes shopping during a sale at his favorite store. The sale is for 20% off all games. He uses a 10% off coupon on his purchase. Timothy also purchases a specialty item for $18 on which the coupon and sale do not apply. His purchase over all has a sales tax of 8%. Which function below models the total cost (c) of his purchase if Timothy buys g dollars worth of games?

c(g)=1.08(0.9(0.8g)+18)

c(g)=0.9(0.8(1.08g)+18)

c(g)=0.08(0.1(0.2g)+18)

c(g)=1.08(0.1(0.8g)+18)