Which of the Following Is Correct Concerning Opportunity Cost

Multiple Choice

Which of the following is correct concerning opportunity cost?

A) Except to the extent that you pay more for them,opportunity costs should not include the cost of things you would have purchased anyway.
B) To compute opportunity costs,you should subtract benefits from costs.
C) Opportunity costs and the idea of trade-offs are not closely related.
D) Rational people should compare various options without considering opportunity costs.