What item type should you use for inventory that you assemble from other items?

The correct choice is inventory assembly, which is specifically designed for items that are created from a combination of other inventory items. When you have a product that you assemble by putting together various components, using the inventory assembly item type allows you to track each of the individual components and also keep an accurate count of the finished assembly. This item type not only helps in managing inventory levels effectively but also streamlines the process of creating finished goods from different parts.

On the other hand, while an inventory part refers to items that are sold as is, it does not provide the assembly functionality needed to manage the components involved in creation. A group item is used when you sell a combination of products together without necessarily assembling them, which is different from creating a new item from parts. Lastly, a non-inventory part is typically used for items that you purchase but do not track quantitatively in inventory, which doesn't align with assembling products from other inventory items. Thus, inventory assembly is the correct choice for tracking the assembly of products made from multiple inventory items.