A computer technician bills $30 initial consulting fee plus $40 for every half-hour of labor performed. Then 8% sales tax is added on to this subtotal. What formula expresses this billing rate to a customer who requires n hours of work? A. 30 + 40n x .08 B. 1.08 (30 + 40n) C. [(30 + 40) x n] x .08 correctD. 1.08 (30 + 80n)