Which of the Following Is Untrue

Which of the following is untrue?

A) An opportunity cost represents the cost of an opportunity that has been lost.
B) Some costs double when the volume of sales doubles.
C) Semi variable costs have a fixed and a variable cost component.
D) A direct cost is a cost that can be traced to a cost object relatively easily.
E) An incremental cost is a cost that does not change as a result of a decision.