According to the PMBOK® Guide, specifically the section on the Role of the Project Manager, PMI defines the necessary skills through the PMI Talent Triangle®. This framework emphasizes that a project manager needs a balance of three key skill sets to be effective in today’s complex business environments:

Technical Project Management (Project Management Knowledge): The knowledge, skills, and behaviors related to the specific domains of Project, Program, and Portfolio Management. This is the technical core of the job.

Leadership: The knowledge, skills, and behaviors needed to guide, motivate, and direct a team to help an organization achieve its business goals.

Strategic and Business Management: The performance-enhancing knowledge and expertise in the industry and organization that improves performance and better delivers business outcomes. This allows the Project Manager to understand the " big picture " of why the project is being undertaken.

Why other options are incorrect:

Option A: While " bilingualism " and " experience " are valuable, they are not categorized as core " competencies " within the formal PMI Talent Triangle framework.

Option B: PMP certification and post-graduate education are credentials or qualifications, not competencies. A competency is the ability to do something effectively, whereas a degree is a formal recognition of study.

Option D: Communication skills are indeed a subset of leadership, and availability to travel is a job requirement/constraint, not a professional competency required by the global standard for project management.