For part B and part C I'm looking for how to write the constraint.

A manufacturing company must choose among a series of new investment projects. The net present value (NPV) of the future stream of returns and capital requirements for each project, along with the available capital funds over the next three years, are summarized as follows. Capital Budget Candidate Project A B D E F NPV Payoff $4,000 $6,000 $10,500 $4,000 $8,000 $3,000 Year 1 Cap Req. $3,000 $2,500 $6,000 $2,000 $5,000 $1,000 Year 2 Cap Req. $1,000 $3,500 $4,000 $1,500 $1,000 $500 Year 3 Cap Req. $4,000 $3,500 $5,000 $1,800 $4,000 $900 $10.500 $7,000 $8,750 (a) Develop a binary programming model to determine the projects in which to invest, with the goal of maximizing NPV. You do not need to solve the LP. (b) Suppose that exactly one of projects A or B (but not both) must be undertaken. Write the constraint that would represent this business requirement in the LP formulation. (c) (Bonus) Suppose that if project C is undertaken, then project D must also be undertaken. (Project D may be undertaken even if project C is not.) Write the constraint that would represent this business requirement in the LP formulation