See image for context on the problem.

Please solve the following:

$1)$ Let A$,$ B$,$ C$,$ and D be binary variables such that a value of $1$ represents selecting the corresponding opportunity.$$ For example,$$ A $=1$ means that opportunity A is selected. Which ones of the following constraints model the mutually exclusive requirements?

Group of answer choices

A $+$ B $>=1$ and C $+$ D $>=1$

A $+$ B and C $+$ D

A $+$ B and C $+$ D

A $+$ B $+$ C $+$ D

$2)$ Let A and C be binary variables such that a value of $1$ represents selecting the corresponding opportunity.$$ For example,$$ A $=1$ means that opportunity A is selected. Which constraint enforces the contingency restriction that does not allow C to be selected unless A is selected?

Group of answer choices

A $+$ C

C A

A C

A $-$ C

A $-$ C $>=1$

$3)$ What is the optimal selection of investment opportunities? Choose all the ones that are included in the optimal portfolio.

Group of answer choices

A

B

C

D

E

F

G

$4)$ What is the net present value of the optimal solution?