Consider the following chart

Reference: Order Cycle Chart

Which if the following is correct with respect to this chart

A$.$The chart shows a stepwise function because the daily demand drops at a constant rate

B$.$As soon as the inventory level crosses the reorder point line a new order should be immediately placed

C$.$When the inventory level drops below the line that separates the light green area from the darker green area we have a shortage

D$.$If safety stock is half the reorder point we know that shortages cannot occur, however, the holding cost can be very high

E$.$All of the above are correct