One hundred twenty units of end item Z are needed at the beginning of week 7 . Take into account that on hand there are 40 units of Z, 70 units of A,100 units of B, and 30 units of C. Also, there is a scheduled receipt of 20 units of component C in week 4 , Lesad times are two weeks for Z and B, ans one week for the other components. Lot-for-lot ordering will be used for all items.