Ans = A and D
A. The sandbox org will be locked. Administrators cannot modify metadata: When a change set is being deployed, the sandbox org from which it is originating will be locked to prevent any changes to the metadata during the deployment process. This ensures that the metadata being deployed remains consistent and avoids conflicts or unintended changes.

D. The production org will be locked. Users will still be able to Read/Write data to the org: While the production org undergoes the deployment process, it will not be locked for users in terms of data access. Users will still be able to read and write data to the org as usual. The locking behavior primarily applies to metadata changes and not data operations.