Math
posted by Anonymous .
A computer program is designed so that, when a number is entered, the computer output is obtained by multiplying the number by 3 and then subtracting 4 from the product. If the output that results from entering a number x is then entered, which expression represents, in terms of x, the final output?
(A) 3x  8
(B) 3x  12
(C) 9x  8
(D) 9x  16
(E) 6x + 9

I think it is D. I am not 100% positive though.