The correct answer is: A. relevant total costs.
Relevant ordering costs are the costs associated with placing an order, such as the cost of the purchase order itself, the cost of shipping the goods, and the cost of any inspection or testing that is required. Relevant carrying costs are the costs associated with holding inventory, such as the cost of storage space, the cost of insurance, and the cost of obsolescence. Relevant total costs are the sum of relevant ordering costs and relevant carrying costs.
Contribution costs are the costs that are directly attributable to a particular product or service, such as the cost of materials, the cost of labor, and the cost of overhead. Throughput costs are the costs associated with producing a product or service, such as the cost of materials, the cost of labor, and the cost of overhead. Optimized costs are the costs that are incurred when a company is operating at its optimal level of efficiency.
In conclusion, relevant total costs are the sum of relevant ordering costs and relevant carrying costs.