In an all-integer linear program, .
a. all decision variables must be integer.
b. all objective function coefficients and right-hand side values must be integer.
c. all right-hand side values must be integer.
d. None of the provided answers is correct
e. all objective function coefficients must be integer.

The option a) all decision variables must be integer is correct.In an all-integer linear program , all decision variables must be integer.

Step-by-step explanation:

In an all-integer linear program , all decision variables must be integer.

Because :In a integer linear program there are two main reasons for using integer variables while modeling problems .The integer variables represent only the quantities if it is an integer. The integer variables represent decisions variables and therefore should only take on the value 0 or 1.Therefore option a) all decision variables must be integer is correct.