Answer:
D. stockpiled inventory, adding to the cost of providing auto parts.
Step-by-step explanation:
Stockpiling is the process of accumulating a large stock of materials, goods, or inventory items with in order to avoid stock-outs that result in losing customers to competitors.
In order to stockpiled inventory, appropriate provision is usually made in the budget in order to increase the cost of making inventory available at all time.
Therefore, to avoid this problem and keep his business customers, Steven most likely stockpiled inventory, adding to the cost of providing auto parts.