Microsoft's marginal cost of the 100th copy of Windows 2002 is ________:
A) the maximum amount that someone is willing to pay for the 100th copy of Windows 2002
B) opportunity cost of producing 100 copies of Windows 2002
C) opportunity cost of producing the 100th copy of Windows 2002
D) maximum amount that she is willing to pay for 100 copies of Windows 2002
Answer: C