The best way to ensure effective change management in an IS environment is to have user-prepared detailed test criteria for acceptance testing of the software. This ensures that changes are thoroughly evaluated and validated by the end users who understand the business requirements and processes. Adequate testing by the development team (Option A) does not ensure that changes meet user needs. User authorization procedures for application access (Option C) and controlled access to production source and object programs (Option D) are related to security and access control rather than directly ensuring effective change management.