A product has a demand of 4000 units per year. Ordering cost is $20, and holding cost is $4 per unit per year. The cost-minimizing solution for this product is to order:
A) all 4000 units at one time.
B) 200 units per order.
C) every 20 days.
D) 10 times per year.
E) none of the above
Answer: B