Explanation
The project manager should contact the project management office (PMO) for assistance after learning that a similarly time-consuming project was executed previously in the organization. A PMO is a department or group within an organization that provides centralized guidance, governance, standards, best practices, resources, and oversight for project managementactivities. A PMO can help the project manager by providing access to historical data, lessons learned, templates, tools, methodologies, and expertise from previous projects that can be useful for planning and executing the current project.

The environmental factor would be impacted the most by requirements for a project to implement an air quality control system at a coal plant. This is because coal combustion produces various air pollutants, such as particulate matter (PM), sulfur dioxide (SO2), nitrogen oxides (NOx), carbon dioxide (CO2), and mercury, that can harm human health and the environment12. An air quality control system can reduce the emissions of these pollutants by using different technologies, such as low NOx burners, flue gas desulfurization, electrostatic precipitators, and carbon capture and storage23. However, these technologies also have environmental impacts, such as water consumption, waste generation, energy consumption, and greenhouse gas emissions4. Therefore, the project manager should consider the environmental factor in terms of the project scope, objectives, constraints, risks, and stakeholders, and evaluate the trade-offs and benefits of different air quality control options5. References = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 3: Project Scope Management, p. 97; Update on air pollution control strategies for coal-fired power plants; AQCS Air Quality Control Systems; NOx control for high-ash coal-fired power plants in India; Coal Dust Control

The RACI (Responsible, Accountable, Consulted, Informed) matrix is used to document which resources are responsible for which tasks. The RACI matrix is a tool that helps to clarify roles and responsibilities on a project. It assigns a level of responsibility to each resource involved in the project. Reference: CompTIA Project+ Study Guide Section 3.4.
The project manager should use a RACI matrix to document which resources are responsible for which tasks. A RACI matrix is a type of responsibility assignment matrix (RAM) that plots the roles and responsibilities of resources on a project team. RACI stands for Responsible, Accountable, Consulted, and Informed. A RACI matrix can help to clarify who does what on a project, avoid confusion and duplication of work, and improve communication and collaboration among team members.

Operational security (OPSEC) is a process that prevents sensitive information from getting into the wrong hands by viewing operations from the perspective of an adversary1. Facility access is a form of OPSEC that controls who can enter and exit a physical location where sensitive data or equipment is stored or processed. Facility access can include measures such as locks, alarms, badges, biometrics, guards, and cameras. The other options are not correct because:
Mobile device compliance is a policy that ensures that mobile devices used by employees or contractors meet certain security standards and requirements, such as encryption, password protection, antivirus, and remote wipe. Mobile device compliance is not a form of OPSEC, but rather a form of data security or device management.
Background screening is a process that checks the criminal, financial, and employment history of a potential employee or contractor before hiring them. Background screening is not a form of OPSEC, but rather a form of human resource management or risk mitigation.
Multifactor authentication is a method that requires users to provide two or more pieces of evidence to verify their identity before accessing a system or service, such as a password, a code, a token, or a biometric. Multifactor authentication is not a form of OPSEC, but rather a form of access control or identity management. Reference = CompTIA Project+ Study Guide: Exam PK0-005, 3rd Edition, Chapter 10: Executing and Closing Projects, page 314; CompTIA Project+ Certification Exam Objectives, Domain 3: Project Execution, Objective 3.2: Given a scenario, execute and monitor project tasks using traditional methodologies; What is Operational Security? The Five-Step Process, Best Practices, and More

The RACI (Responsible, Accountable, Consulted, Informed) matrix is used to document which resources are responsible for which tasks. The RACI matrix is a tool that helps to clarify roles and responsibilities on a project. It assigns a level of responsibility to each resource involved in the project. References: CompTIA Project+ Study Guide Section 3.4.
The project manager should use a RACI matrix to document which resources are responsible for which tasks. A RACI matrix is a type of responsibility assignment matrix (RAM) that plots the roles and responsibilities of resources on a project team. RACI stands for Responsible, Accountable, Consulted, and Informed. A RACI matrix can help to clarify who does what on a project, avoid confusion and duplication of work, and improve communication and collaboration among team members.