Data Corpis Considering Which of 4 Different Projects to Undertake in in Order

Multiple Choice

Data Corp.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 stating that project 3 can be undertaken only if project 2 is undertaken?

A) X2 + X3 ≤ 1
B) X2 - X3 ≤ 0
C) X3 - X2 ≤ 0
D) X2 - X3 ≤ 1
E) X3 - X2 ≤ 1