What are implicit costs? An implicit cost is OA. a cost incurred in the short run. OB. a cost that changes as output changes. C. a nonmonetary opportunity cost. OD. the highest-valued alternative that must be given up to engage in an activity. E. a cost that remains constant as output changes. How are implicit costs different from explicit costs? OA. An explicit cost is a cost that involves spending money, while an implicit cost is a nonmonetary cost. B. An explicit cost is not an opportunity cost, while an implicit cost is an opportunity cost. OC. An explicit cost is a cost incurred holding output constant, while an implicit cost is a cost incurred as output changes. D. An explicit cost is a cost incurred in the short rn, while an implicit cost is a cost incurred in the long run. OE. Both. and b.