The correct answer to the given question is option c) the cost of producing one more unit of output.

The marginal cost is defined as the incremental cost incurred for producing one additional unit of a product or output. It may or may not exceed the marginal benefit, which in turn is the benefit associated with one additional unit of a product. Usually. the marginal cost consists of the variable costs and not the fixed costs within a relevant range of production for a given period of time.