(20 pts) NBC finished next year's material planning based on the aggregate plans for next year that it had developed for several families of bikes it manufactures. However, NBC just received additional orders and needs to deliver 90 S-Tiger bikes in week 12, and 90 Tiger bikes in week 9. The model, Tiger, is similar to S-Tiger but with fewer features. The production of S-Tiger and Tiger involves different kinds of parts items, where some items can be made at the plant and the others are purchased from regional suppliers. Let's label S-Tiger and Tiger by Item A and Item B. The other types of parts items were labeled as Items C, D, E, and F. Item A is made by assembling 1 item B, 2 items C, and 2 items D. Each B includes 2 items C and 2 items E. Each C needs 1 item D, 1 item E and 1 item F for assembly. The table below shows the lead times and quantities on hand right now (i.e. week 0) at the company's plant for items A, B, C, D, E and F, respectively.

Must use a lot for lot approach

Table
Item	Lead time (week)	Quantity on hand
A	1	10
B	2	20
C	4	135
D	1	80
E	4	60
F	3	200