A store buys t-shirts from a supplier in China. The supplier offers the following purchasing options to the store:
Quantity ordered: [1-2,499], [2500 or more]
Unit Price: $35 (for 1-2,499), $32 (for 2500 or more)
The store sells 500,000 t-shirts each year. The annual carrying cost of t-shirts is 25%, and the ordering cost is $40. What order quantity would give the store the lowest total acquisition cost? Show your process.