The correct answer is A. Administrative salaries.
Product costs are the costs that are directly associated with the production of a good or service. They include direct materials, direct labor, and manufacturing overhead. Administrative salaries are not directly associated with the production of a good or service, so they are not considered product costs.
Direct materials are the materials that are used in the production of a good or service and that can be easily traced to the finished product. For example, the wood used to make a table is a direct material.
Direct labor is the labor that is directly involved in the production of a good or service. For example, the labor of the workers who assemble the table is direct labor.
Manufacturing overhead is all of the other costs that are incurred in the production of a good or service, but that cannot be easily traced to the finished product. For example, the cost of the factory building and the cost of the plant manager’s salary are manufacturing overhead costs.
Administrative salaries are the salaries of the employees who are responsible for the overall management of the company. These employees are not directly involved in the production of goods or services, so their salaries are not considered product costs.