The programming project leader solely reviewing test results before approving the transfer to production would be a weakness in procedures for controlling the migration of changes to production libraries, because it violates the principle of segregation of duties, and it exposes the production libraries to the risk of unauthorized or erroneous changes. The programming project leader is responsible for developing and testing the changes, but not for approving and deploying them. The approval and deployment of the changes should be done by an independent and authorized party, such as the change control board or the operations manager. The other options are not weaknesses, but rather good practices, because:

Option B: Test and production programs being in distinct libraries is a good practice, because it prevents the accidental or intentional overwriting or mixing of the test and production programs, and it ensures the integrity and security of the production libraries.

Option C: Only operations personnel being authorized to access production libraries is a good practice, because it restricts the access and modification of the production libraries to the qualified and accountable staff, and it prevents the unauthorized or inappropriate access or modification of the production libraries by other parties.

Option D: A synchronized migration of executable and source code from the test environment to the production environment being allowed is a good practice, because it ensures the consistency and completeness of the changes, and it avoids the potential errors or discrepancies that may arise from the manual or partial migration of the changes. References = Risk and Information Systems Control Study Manual, 7th Edition, ISACA, 2020, p. 215.