Which of these can you assign books bought in Apple Business Manager to?

The correct option is users with a Managed Apple Account because these accounts are specifically designed for organizations that leverage Apple Business Manager for deployment and management. Managed Apple Accounts allow businesses to manage the distribution of apps and content, including books, efficiently. This feature ensures that the organization can maintain control over the content associated with these accounts, facilitating easy reassignment or retrieval as employees change or leave the organization.

In comparison, regular Apple IDs and iCloud account holders do not offer the necessary management capabilities. Books and other purchases are tied to individual, personal accounts that lack administrative oversight, making them unsuitable for organizational use. Admin accounts alone would not be appropriate unless those accounts are also aligned with user accounts that can be managed under the Apple Business framework. Thus, only Managed Apple Accounts provide the right structure for assigning and managing purchased books in an organizational context.