4. One unit of A is made of one unit of B and one unit of C. B is made of four units of C and one unit each of E and F. C is made of two units of D and one unit of E. E is made of three units of F. Item C has a lead time of one week; Items A, B, E, and F have twoweek lead times; and Item D has a lead time of three weeks. Lot-for-lot sizing is used for ltems A, D, and E; lots of size 50, 100, and 50 are used for ltems B, C, and F, respectively Items A, C, D, and E have on-hand (beginning) inventories of 20, 50, 100, and 10, respectively; all other items have zero beginning inventory. We are scheduled to receive 10 units of A in Week 1,100 units of C in Week 2, and 100 units of D in Week 3 ; there are no other scheduled receipts. a. Draw the product tree of the end item A, and determine the low-level codes of all the items in the tree. b. What is the minimum number of weeks that you should include in the planning horizon to make the MRP records feasible? 4. One unit of A is made of one unit of B and one unit of C. B is made of four units of C and one unit each of E and F. C is made of two units of D and one unit of E. E is made of three units of F. Item C has a lead time of one week; Items A, B, E, and F have twoweek lead times; and Item D has a lead time of three weeks. Lot-for-lot sizing is used for ltems A, D, and E; lots of size 50, 100, and 50 are used for ltems B, C, and F, respectively Items A, C, D, and E have on-hand (beginning) inventories of 20, 50, 100, and 10, respectively; all other items have zero beginning inventory. We are scheduled to receive 10 units of A in Week 1,100 units of C in Week 2, and 100 units of D in Week 3 ; there are no other scheduled receipts. a. Draw the product tree of the end item A, and determine the low-level codes of all the items in the tree. b. What is the minimum number of weeks that you should include in the planning horizon to make the MRP records feasible