Consider the modified exercise model below. Your goal is to choose the optimal mix of projects within the following assumptions:

$$ If projects #$2$ and #$4$ are both chosen, then an additional $2$ people must be used.

$12$ people are available

$$ Projects #$1$ and #$3$ are mutually exclusive.

$$ $$2,000$ is available in Time $0.$

A$)$ Considering the assumptions, what formula needs to go in cell B$15?$

B$)$ Considering the assumptions, what formula needs to go in cell C$15?$

C$)$ Considering the assumptions, what formula needs to go in cell B$17?$

D$)$ In $$solving$$ this problem you

Maximize cell:

By changing cells:

Subject to the following constraints: