The correct answer is A. direct cost.
A direct cost is a cost that can be easily and specifically traced to a particular cost object. For example, the cost of raw materials used to make a product is a direct cost of that product.
An indirect cost is a cost that cannot be easily or specifically traced to a particular cost object. For example, the cost of the plant manager’s salary is an indirect cost of the products made in the plant.
A line cost is a cost that is directly related to the production of goods or services. For example, the cost of direct materials is a line cost.
A staff cost is a cost that is not directly related to the production of goods or services. For example, the cost of the plant manager’s salary is a staff cost.
In conclusion, a cost that is related to a specific cost object and economically traceable is a direct cost.