A. Opportunity cost is a foregone benefit (inflow), not a cash outflow.

B. Opportunity cost is a foregone benefit (inflow), not a cash outflow.

C. Opportunity cost is a foregone benefit (inflow), not a cash outflow.

D. Opportunity cost is the benefit to net income (inflow) that is lost by not using a limited resource for its best alternative use. When there is no excess capacity in a factory, the net benefit forgone from making a component is the contribution margin given up by not being able to make something else instead or the income that could be earned from using the factory for an alternative use, such as renting it to another manufacturer.