The main disadvantage of introducing constraints into a linear program that enforce some or all of the decision variables to be either integer or binary is that:

Question $22$ options:

A$)$

the solutions will no longer be optimal.

B$)$

the constraints are difficult to formulate.

C$)$

the programs may take longer to solve.

D$)$

Excel can no longer be used to solve the program.

E$)$

we cannot have "yes$-$or$-$no$"$ decisions in the linear program.