Opportunity cost

Guys,

We all know what opportunity cost is, now I have a question.

Project A: NPV 100

Project B: NPV 200

Project C: NPV 500

Project C would be selected at what opportunity cost, 200 or 300 ?

(Only at cost of project B, or sum of A+B ?)

" I think" it should be 300 as this is what company looses while selecting project C.

 I doubt becoz the defination says,

"relative cost of one alternative in terms of the next-best alternative"

any more thoughts?

 

The organization can select only one project at a time so the opportunity cost (lost value) should be considered only for next best alternative. The answer should be 200.

 Thanks!