The cost C (in dollars) of manufacturing x number of high-quality computer laser printers in C(x)=15x^4/3+15x^2/3+600,000 Currently, the level of production is 1,728 printers, but that level is increasing by 50 every month. At what rate is the cost increasing every month?

• A. $12, 042 per month
• B. $13, 042 per month
• C. $14, 042 per month
• D. $15, 042 per month