The Owner of an Appliance Store Expects to Sell 500

The owner of an appliance store expects to sell 500 toasters this year.Each toaster costs her $6 dollars to purchase,and each time she orders a shipment of toasters,it costs $30.In addition,it costs $4 a year to store each toaster.Assuming the toasters sell out at a uniform rate and that the owner never allows herself to run out of toasters,how many toasters should be ordered in each shipment to minimize the annual cost? (Round any fractional amounts.)

A) 87
B) 22
C) 44
D) 33