A company that tracks inventory and places an order for a lot size Q when the inventory declines to the reorder point (ROP) is using

A) continuous review.
B) daily review.
C) occasional review.
D) periodic review.

The given scenario describes the continuous review system, where the inventory level is continuously monitored, and an order is placed to replenish the inventory when it reaches the reorder point. In contrast, periodic review system (D) involves checking the inventory levels at fixed time intervals and placing orders accordingly. Occasional review (C) does not refer to any specific inventory system, and daily review (B) is not a common type of inventory system. Hence, the best choice in this scenario is A) continuous review.