正解:A
Upgrading macOS requires volume ownership, tied to an admin account with permissions to modify the system volume. The macOS Deployment Reference states, "To install or upgrade macOS, the user must have volume ownership, which allows the system to authenticate the operation against the secure volume." Option B is for MDM updates, C is insufficient alone in newer macOS versions, and D is for content, not upgrades.
Reference:
macOS Deployment Reference, "Software Updates" section.
Apple Platform Security Guide, "System Volume Protections" section.