please explain how you got your answer

Part 1 018 Points: 0 of 3 Save The demand for subassembly S is 130 units in week 7. Each unit of S requires 1 unit of T and 1 unit of U. Each unit of T requires 2 units of V, 2 units of W. and 1 unit of X. Finally, each unit of U requires 1 unit of Y and 2 units of Z. One firm manufactures all items. It takes 2 weeks to make S. 1 week to make T. 2 weeks to make U, 1 week to make V, 3 weeks to make W. 1 week to make X, 2 weeks to make Y, and 1 week to make Z. Click the icon to view the product structure and the time phased product structure. Construct a gross material requirements plan (type 0 if the input box is not used). Item Week 4 1 2 3 5 Lead Time (weeks) 6 7 S Gross req Order release 2 x More info The product structure. The time-phased product structure. Level S WT x