The closing phase is when the project manager and the team finalize the project, deliver the outcomes to the customer, obtain formal acceptance, conduct lessons learned, and hand over the project to the operations team. Identifying the baseline go-live date, the operational training, and the handoff procedures are part of the closing activities that ensure a smooth transition and closure of the project. References = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 14: Closing Projects, p. 333-334.

Operational security is the process of identifying, protecting, and controlling sensitive information and activities from unauthorized access or disclosure. Operational security includes background screenings for personnel who need to access classified or restricted information or resources, as well as implementing policies and procedures to prevent leaks, breaches, or espionage. Operational security is essential for government projects that involve national security, defense, intelligence, or law enforcement.
Operational security is different from data security, which is the process of safeguarding data from unauthorized access, use, modification, or destruction. Data security includes encryption, authentication, authorization, backup, and recovery of data. Operational security is also different from physical security, which is the process of securing physical assets, such as equipment, data, or personnel, from unauthorized access or damage. Physical security includes locks, alarms, cameras, guards, and fences. Operational security is also different from digital security, which is the process of protecting digital devices, networks, and systems from cyberattacks, malware, or hacking. Digital security includes firewalls, antivirus, VPN, and passwords. Reference = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 9: Security Management1; CompTIA Project+ Certification Study Guide, 3rd Edition, Chapter 9: Security Management2; What is Operational Security (OPSEC)?3

Explanation
A RACI chart would be the most useful option for the project manager to illustrate roles for major project activities for an upcoming project kickoff. A RACI chart is a visual representation of a RACI matrix that shows who is responsible, accountable, consulted, and informed for each task or activity in a project using a table format. A RACI chart can help to communicate anddocument the roles and expectations of each team member and stakeholder for the project and ensure alignment and agreement.

The project manager should consult a Gantt chart after the sponsor states that the project is taking too long to
complete. A Gantt chart is a graphical tool that shows the schedule of a project, including the start and end
dates, durations, dependencies, milestones, and progress of each task or activity. A Gantt chart can help to
monitor and control the project timeline and identify any delays, variances, or issues that may affect the
project completion.

A wiki knowledge base is a tool that allows the project team to store, organize, and share information that is captured throughout the life cycle of a project. A wiki knowledge base is stored in a centralized location that is easily accessible to all stakeholders via a web browser. A wiki knowledge base also provides search functionality that enables the users to find the information they need quickly and easily. A wiki knowledge base can help the project team to document the project requirements, scope, schedule, budget, quality, risks, issues, lessons learned, and best practices.
A wiki knowledge base is different from a secure folder, which is a tool that protects the files and folders from unauthorized access or modification. A secure folder may not be easily accessible to all stakeholders, and may not provide search functionality or collaboration features. A wiki knowledge base is also different from a real-time, multiauthoring editing software, which is a tool that allows the project team to create and edit documents simultaneously and synchronously. A real-time, multiauthoring editing software may not be suitable for storing large amounts of information, and may not provide the same level of organization and structure as a wiki knowledge base. A wiki knowledge base is also different from a digital whiteboard, which is a tool that allows the project team to brainstorm, visualize, and communicate ideas. A digital whiteboard is not designed for storing information, and may not provide the same level of search functionality or security as a wiki knowledge base. Reference = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 3: Project Communications Management1; CompTIA Project+ Certification Study Guide, 3rd Edition, Chapter 3: Project Communications Management2; The 15 best collaboration tools for productive teams3