Riker Cois Considering Which of 4 Different Projects to Undertake in in Order

Multiple Choice

Riker Co.is considering which of 4 different projects to undertake in order to maximize its net present value (NPV) .Define Xi as a binary variable that equals 1 if project i is undertaken and 0 otherwise,for i = 1,2,3,4.The NPV and required capital (in millions) for each project are listed below.
Which of the following represents the constraint(s) stating that project 1 must be undertaken and at least one of the other projects must be undertaken?

A) X1 + X2 ≤ 1,and X1 + X3 ≤ 1,and X1 + X4 ≤ 1
B) X1 ≥1,and X2 + X3 + X4 ≥ 1
C) X1 + X2 ≥ 1,and X1 + X3 ≥ 1,and X1 + X4 ≥ 1
D) X1 ≥1,and X2 + X3 + X4 ≤ 3
E) X1 + X2 + X3 + X4 ≥ 2