What controls this functionality?

You must ensure that a bill of material will explode to generate sub-items in as ales order.

What controls this functionality? Choose the correct answer.
A . The item category group of the material master in the sub-item
B . The item usage during the item category determination of each sub-item
C . The item type in the item category of the main item
D . The structure scope in the item category of the main item

Answer: D