clamp has $1$ handle and $1$ casting. Each housing has $2$ bearings and $1$ shaft. 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.

$\backslash$table$[[$Number$,$Item$],[$I$,$Spring ${?}_{(2)}$