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.
What is the proper objective function?

A) Max X1 + X2 + X3 + X4
B) Min 60X1 + 50X2 + 40X3 + 20X4
C) Max 60X1 + 50X2 + 40X3 + 20X4
D) Max 7X1 + 10X2 + 6X3 + 3X4
E) Max 170(X1 + X2 + X3 + X4)