2 A company must meet the following demands on time:

month 1, 1 unit; month 2, 1 unit; month 3, 2 units; month 4, 2 units. It costs $4 to place an order, and a $2 per-unit holding cost is assessed against each month’s ending inventory. At the beginning of month 1, 1 unit is available.

Orders are delivered instantaneously.

a Use a backward recursion to determine an optimal ordering policy.

b Use the Wagner–Whitin method to determine an optimal ordering policy.

c Use the Silver–Meal heuristic to determine an ordering policy.