Final answer:
The correct statements about adding sub-categories in QuickBooks Online are: you can add up to 4 category and sub-category levels, including the parent, you can edit existing items to assign them to a sub-category, and you can create a sub-category when setting up a new item.
Step-by-step explanation:
The correct statements about adding sub-categories to the product and services list in QuickBooks Online are:
- You can only add up to 4 category and sub-category levels, including the parent.
- You can edit existing product/service items to assign them to a sub-category.
- You can create a sub-category when you’re setting up a new product/service item.
These statements accurately describe the limitations and capabilities of adding sub-categories in QuickBooks Online.