The demand for subassembly $S$ is $100$ units in week $7.$ Each unit of $S$ requires $2$ units 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 $2$ units 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 $U,2$ weeks to make $V,3$ weeks to

make W$,2$ weeks to make $x,2$ weeks to make Y$,$ and $1$ week to make $Z.$

a$)$ Choose the correct product structure.

A$.$

Level

B$.$

c$.$

Level

D$.$

Level