Economic cost can best be defined as: (a) any contractual obligation that results in a flow of money expenditures from an enterprise to resource suppliers. (b) any contractual obligation to labor or material suppliers. (c) a payment that must be made to obtain and retain the services of a resource. (d) all costs exclusive of payments to fixed factors of production.

(d) all costs exclusive of payments to fixed factors of production.

Explanation:

The cost involved in the first three options is considered by economists as accounting cost. Economic cost involves the accounting cost, but it is added to the opportunity cost, which is the remuneration that an economic agent fails to receive for practicing one economic activity and not another.

For example, a business owner has fixed production costs, but it should add to his opportunity cost to be working in that firm rather than another economic activity.

107x106 is the answer