Consider a fixed-period system (FPS). Choose the most accurate statement regarding an FPS.
a. It orders a fixed quantity of items when the inventory position reaches or drops below the reorder point (r).
b. It orders sufficient stock at the time of review to bring the inventory position up to the replenishment level (M).
c. It maintains a constant order quantity in every review period.
d. It checks the inventory position on a continuous basis.