One unit of A is made of two units of B and one unit of C. B is made of three units of D and one unit of F. C is composed of three units of B, one unit of D, and four units of E. D is made of one unit of E. Item C has a lead time of one week; Items A, B, E, and F have two-week lead times; and Item D has a lead time of three weeks. Lot-for-lot lot sizing is used for Items C, E, and F; lots of size 20, 40, and 160 are used for Items A, B, and D, respectively. Items A, B, D, and E have on-hand (beginning) inventories of 5, 10, 100, and 100, respectively; all other items have zero beginning inventories. We are scheduled to receive 10 units of A in Week 3, 20 units of B in Week 7, 40 units of F in Week 5, and 60 units of E in Week 2; there are no other scheduled receipts. If 20 units of A are required in Week 10, use the low-level- coded bill of materials (product structure tree) to ﬁnd the necessary planned order releases for all components.