Mr$.$ Drucker uses a periodic review system to manage the inventory in his dry goods store. He likes to maintain $15$ sacks of sugar on his shelves based on the annual demand figure of $225$ sacks. It costs$$ $$2$ to place an order for sugar and costs$$ $$1$ to hold a sack in inventory for a year. Mr$.$ Drucker checks inventory one day and notes that he is down to $9$ sacks; how much should he$$ order?

A$.$

$15$ sacks

B$.$

$30$ sacks

C$.$

$9$ sacks

D$.$

$6$ sacks