Could someone explain me how to perform this problem, please?

Item: C OH: 10 LT: 1 SS: 0 Q: 50 Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Item: D OH: 20 LT: 2 SS: 0 Q: 95 Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Item: E OH: 15 LT: 2 SS: 0 Q: 55 Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Problem 9-17 (Algo) Each unit of A is composed of one unit of B, two units of C, and one unit of D. C is composed of two units of D and three units of E. Items A, C, D, and E have on-hand Inventories of 20, 10, 20, and 15 units, respectively. Item B has a scheduled receipt of 10 units in Perlod 1, and C has a scheduled receipt of 50 units in Period 1. Lot-for-lot (L4L) is used for Items A and B. Item C requires a minimum lot size of 50 units. D and E are required to be purchased in multiples of 95 and 55, respectively. Lead times are one period for Items A, B, and C, and two periods for Items D and E. The gross requirements for A are 30 in Perlod 2,30 in Perlod 5, and 40 in Period 8. Find the planned-order releases for all items. (Leave the cells blank, whenever zero (0) is required.) Period: 8 Item: A OH: 20 LT: 1 SS: 0 Q: L4L Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Item: B OH: 0 LT: 1 SS: 0 Q: L4L Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases