Which of the following statements is TRUE regarding various inventory. systems?

A single$-$period system is the best fit to manage replacement parts for Caterpillar's construction equipment.

A fixed$-$order quantity system is applicable to manage coffee cup inventories at a deli shop.

In single$-$period systems, the order size is determined by the tradeoff between holding cost and ordering cost.

In fixed$-$order quantity systems, the order size may include safety stock.