According to the PMBOK® Guide and the Standard for Portfolio Management, a portfolio is a high-level component of the organizational hierarchy designed to bridge the gap between strategy and execution.

Strategic Objectives (Choice A): This is the correct definition. A portfolio is a collection of projects, programs, subsidiary portfolios, and operations managed as a group to achieve strategic objectives. The components of a portfolio are not necessarily related or interdependent; their common denominator is that they all contribute to the organization ' s high-level strategic plan and compete for the same limited organizational resources.

Main Project/CEO (Choice B): A portfolio is not a " main project, " nor is it defined by who supervises it. While a CEO or a Portfolio Review Board may oversee a portfolio, the definition rests on the nature of the work (strategic grouping) rather than the job title of the supervisor.

Same Project Manager (Choice C): Managing multiple projects together simply because they share a project manager does not make them a portfolio. This is more likely a workload management situation. A portfolio is defined by strategic alignment, not by administrative assignment.

Related Projects/Similar Services (Choice D): This definition is closer to Program Management. Programs consist of related projects managed in a coordinated way to obtain benefits. Portfolio components do not need to be related or provide similar services; for example, a construction company ' s portfolio might include a " Hospital Building Project " and a " Company-wide IT Upgrade, " which are unrelated but both strategically vital.

The Portfolio Management process ensures that an organization can prioritize its investments and ensure that the projects and programs being executed are the ones most likely to deliver the intended business value and strategic goals.