During the implement phase， systems acceptance testing does which of the following for the customer？ Select exactly 1 answer（s） from the following：（）。

• A、installation， configuration， and testing， as well as the commissioning of tools and processes in accordance with the operations implementation plan
• B、provision of information regarding customer-specified design requirements and configuration
• C、the migration of network services from an existing state to a future state in accordance with the migration plan
• D、the provision of an objective means of measuring system operability and functionality