Explanation:

- Explicit Cost:

- This is the correct answer.

- It refers to direct, out-of-pocket payments for inputs needed for production.

- Examples include wages, rent, and materials purchased from the market.

- Money Cost:

- Represents the monetary expenses incurred during production.

- Often used interchangeably with explicit costs but may encompass broader financial implications.

- Real Cost:

- Considers the opportunity cost in terms of resource usage and effort.

- Emphasizes the sacrifice involved in using resources (e.g., labor and capital).

- Implicit Cost:

- Involves the opportunity costs of using owned resources.

- Reflects income foregone by employing resources one already owns, such as using one's own building for business instead of renting it out.