A company is considering four possible projects to pursue. It has $12 million to invest in these projects. Using units of millions of dollars, the following table shows the estimated long-run profit (net present value) that each project would generate, as well as the amount of initial investment required to undertake the project. At most, three projects can be pursued. A. Clearly describe what the decision variables are. Include their unit (pounds, products, persons, etc.) and the values they can take (continuous, integer, or binary.) B. Show the 'algebraic form' [or standard form] LP model that can be used to optimize the company's total long-run profit. The model must include the equations of the (1) objective function and (2) all constraints. (Note: You don't have to solve it.)