consider a system with two end items - Item 1 and Item 2

Item 1 requires two units of item A and one unit of item C

Item 2 requires two one of item B and three units of item E

Item A requires one unit of item B and 2 units of item F

Item B requires two units of item C and one unit of item E

Item C requires one unit of item f and three units of item G

Item D requires 2 units of item B and one unit of item C

IDENTITY THE LEVELS FOR THE ITEMS

Format - is there are 2 or more items at a level then write down your answer as A,B,C or A and B and C

eg: Level 0 items : 1 and 2

please answer the following :

Level 1 items :

level 2 items:

level 3 items:

Level 4 items: