Consider the spatial distribution of factories shown in Figure 5-4. The distance between city M and city C is 1 km, and the distance between city C and city D is 7 km. Mr. Fixit is currently in city M and is considering relocating. The urban development agency in city M will develop a subsidy plan to keep Mr. Fixit in the city. Suppose that Mr. Fixit's cost per mile of travel is $2. a. To prevent a move from city M to city C, the minimum weekly subsidy is $. . . . b. To prevent a move from city M to city D, the minimum weekly subsidy is $ . . .