The executive leadership of a Fortune 100 organization approved a major initiative to build a new corporate headquarters in the upcoming fiscal year. During the selection and initiating stage of the construction project, the project manager worked with the Project Sponsor on a Project Charter. The sponsor signed the charter, authorizing the project manager to commit company resources to the project. The PM and team used this high-level information as a basis for preparing detailed project plans, including a detailed schedule and project end date, a time-phased budget, and other plans for all of the 10 PMBOK 6e Knowledge Areas. Before starting project execution, the project manager obtained final sign-off on the baselines for scope, schedule, and cost and for the other plan documents. What life cycle was being used by the project manager and the team