The project manager should **B. Determine the most appropriate life cycle approach for the project**. Given that some requirements are clear and some need more detail, it's important to first decide on the most suitable life cycle approach. This could be predictive, iterative, incremental, agile, or a hybrid approach, depending on the nature of the project, team capabilities, organizational culture, and other factors. This decision will guide how the project is planned and managed, including how requirements are handled. Once the life cycle approach is determined, the project manager can then proceed with tasks such as detailing requirements, planning work, and managing risks.