4. A company has decided to use 0-1 integer programming to help make some investment decisions. There are three possible investment alternatives from which to choose, but if it is decided that a particular alternative is to be selected, the entire cost of that alternative will be incurred (i.e., it is impossible to build one half of a factory). The integer programming model is as follows: Maximize Subject to: 5000X1+ 7000X2+ 9000X3 X1+ X2+ X32 (only 2 may be chosen) 25000X1+ 32000 X2+ 29000X3