Answer:
b. a transaction cost.
Step-by-step explanation:
Transaction costs can be regarded as expenses which is been incurred during the buying or selling of a good/ service.Transaction costs gives representation of the labor which is required in bringing a particular good/ service to the market,. They are cost required to make any economic trade in regards to participation in a market.
example of transaction cost is
Employing a lawyer to draft and enforce a private contract between parties wishing to solve an externality problem.