The marginal cost (MC) of each good or service is the opportunity cost of producing one more unit of it, as illustrate as we move along the PPF, the opportunity cost and the marginal cost of security increases. In the second chart, upward-sloping MC curve shows the rising marginal cost of each additional unit o security produced. Marginal cost (MC) is defined as the opportunity cost of producing another unit of a good or service. Opportunity cost can be illustrated by moving along a PPF unit by unit. Marginal cost curve is upward sloping. MC shows that as ...