Research & Development Corporation is subcontracting four energy-related projects to four independent bidders. For political reasons, each of the bidders has been promised one project. In the following tableau the bid amount are indicated. Project Bidder I II III IV A 20 36 31 17 B 24 34 40 12 C D 22 36 40 38 18 39 35 16 The management wants to minimize the total expenditure for contracts. Set the suitable assignment plan.