2. The product structure tree for end item E follows. The manager wants to know the material requirements for ordered part R that will be needed to complete 120 units of E by the start of week 5. Lead times for items are one week for level 0 items, one week for level 1 items, and two weeks for level 2 items. There is a scheduled receipt of 60 units of M at the start of week 2 and 100 units of Rat the start of Week 1. Lot-for-lot ordering is used. Lovel 0 M(3) 1 (2) 2 R12) N(4)