What does Object.freeze(config) guarantee when config has a nested preferences object?

What does Object.freeze(config) guarantee when config has a nested preferences object?

1. The own data properties of config cannot be written, removed, or reconfigured, but preferences is not frozen automatically.
2. Every object reachable from config becomes deeply immutable.
3. Existing getters are evaluated once and replaced by fixed values.
4. The config binding can no longer be assigned a different object.