幫忙翻譯英文（會計類）

6.Which of the following is not a correct use of the term opportunity cost?
a.Opportunity costs are considered period costs rather than inventoriable costs for accounting purposes.
b.Opportunity costs must be considered by managers when making decisions.
c.Opportunity cost plus the incremental future revenues and costs equal the relevant revenues and costs of any alternative when capacity is constrained.
d.The opportunity cost of holding inventory is the income forgone by tying up money in inventory and not investing it elsewhere.