Could you help to solve it. For B i couldn't know what's wrong i did

As the production planner for Xiangling Hu Products, Inc., you have been given a bill of material for a bracket that is made up of a base, 1 spring, and 4 clamps. The base is assembled from 2 clamps and 1 housing. Each clamp has 1 handle and 2 castings. Each housing has 1 bearing and 2 shafts. There is no inventory on hand. a) Design a product structure noting the quantities for each item and show the low-level coding. Match each number in the structure below with the corresponding item. Bracket Number Item Spring(1) Housing(1) Base(1) Casting(2) IV Shaft(2) Clamp(4) II Clamp(2) Bearing(1) IV Handle(1) Casting(2) Handle(1) IIIb) Determine the gross quantities needed of each item if you are to assemble 100 brackets. Click the icon to view the completed product structure. Base: 100 units (enter your response as a whole number). Spring: 100 units (enter your response as a whole number). Clamp: 600 units (enter your response as a whole number). Housing: 100 units (enter your response as a whole number). Handle: 100 units (enter your response as a whole number). Casting: 400 units (enter your response as a whole number). Bearing: 100 units (enter your response as a whole number). Shaft: 200 units (enter your response as a whole number).The product structure. Bracket Spring (1) Base (1) Clamp(4) Housing(1) Clamp(2) Casting(2) Bearing (1) Shaft 2) Handle Handley Casting(2)