A waste disposal system is shown below. Waste generated in cities A, B and Care respectively ba = 50, bB = 30 and bc = 40 tons/day. Transfer stations D and E are transshipment nodes. Landfills F and G can be assumed to have room for an unlimited amount of waste (o tons/day). Costs ($/ton) to move waste are shown on each link. All links have unlimited capacity. Formulate the problem as a MIN Cost Network Problem to move all the daily waste from the cities to the landfills. bA=50 A CAD=5 CAB=3 CAE=10 CDF=9 F D CBD-6 bg=30 B CEF=12 CBE=8 CDg=13 CCB R=4 E Ccd=11 G CEG=2 bc=40 CCE=7 (a 3 pts) Identify and properly define the decision variables of this problem. (b 3 pts) Identify and properly define the objective function of this problem. Write it EXPLICITELY with all numbers and variables (c-10 pts) Identify and properly define the constraints of this problem (d - 2 pts) Assume that transfer station D can not process more than 60 tons/day of waste. What constraint would you add to your formulation? (e - 2 pts) Assume that transfer station E must process at least 50 tons/day of waste. What constraint would you add to your formulation? (f - 20 pts) Solve it with EXCEL (Upload the solved Excel file with the model, the answer report and the sensitivity report)