After thinking about it for a while, your friend tells you that they may want to open exactly two DCs$.$ She wants these DCs to be located in two of the five candidate cities $($Chihuahua$,$ Mexico City, Monterrey, Puebla, San Luis Potosi$),$ but they should not be located in the same city. The plan would be to distribute all the goods to these two DCs$,$ using trucks. Let's assume that the cost of opening and operating such a DC in any of these cities would be about the same and that the cost of outbound transportation from the DC to the cities is about the same on a per$-$unit per$-$mile basis.