Answer: Opportunity cost
Step-by-step explanation:
A. Opportunity cost can be defined as the next best alternative foregone , it is the cost of profit the business looses while choosing one alternative over other.
B. Fixed cost are those cost that do not change with the level of output produced in the firm.
C. In simple words the direct costs a business pay to the outsiders for running its operations is called explicit cost.
D. Total revenue is the amount of income a company has before deducting its expenses occurred to earn that income.
So from the above explanations we can conclude that value of a business owner's time is an example of opportunity cost.