Hello! $200 is the fixed amount. B doesn't have 200 as part of the problem, so B is eliminated. A is also out, because you add, not subtract. 100 is the amount of boots made, not the amount made per pair of boots. 100 would be the value of "x". The cost per day is $9,200, and 9,200 - 200 is 9,000. With 100 pairs of boots being made each day, 9,000/100 is 90. It would cost $90 per pair of boots made, with the variable "x" being beside it. The correct equation would be C(x) = 90x + 200. The answer is D.
