$2.$ Product $\backslash ($ A $\backslash )$ is an end item and is made from two units of $\backslash ($ B $\backslash ),$ three units of $\backslash ($ C $\backslash )$ and three units of D$.$ B is made of three units of $\backslash ($ E $\backslash )$ and two of $\backslash ($ F $\backslash ).$ C is made of two units of $\backslash ($ F $\backslash )$ and one of D$.$ A and B have a lead time of one week. C and D have lead times of two weeks, and $\backslash ($ E $\backslash )$ and $\backslash ($ F $\backslash )$ have lead times of three weeks. Lot sizes for $\backslash ($ A$,$ B $\backslash )$ and $\backslash ($ D $\backslash )$ are L$4$L$.$ Item $\backslash ($ C $\backslash )$ has a lot size of $50.$ E and $\backslash ($ F $\backslash )$ have a lot size of $100.$ There is $50$ units of item B on hand, and $20$ units of item $\backslash ($ A $\backslash ).$ There is a scheduled receipt for $50$ units of item $\backslash ($ F $\backslash )$ in week three. a$.$ Show the bill of materials $($product structure tree$)$ b$.$ If $200$ units of $\backslash ($ A $\backslash )$ are required in Week $8,$ develop the MRP planning schedule, specifying when items are to be ordered and received.