Assume That We Are Using 0-1 Integer Programming Model to Solve

Multiple Choice

Assume that we are using 0-1 integer programming model to solve a capital budgeting problem and xj = 1 if project j is selected and xj = 0, otherwise.
The constraint (x1 + x2 + x3 + x4 = 2) means that ________ out of the ________ projects must be selected.

A) exactly 1, 2
B) exactly 2, 4
C) at least 2, 4
D) at most 1, 2