The project manager should have assessed the organizational culture at the beginning of the project to understand the readiness and willingness of the functional groups to adopt agile approaches. Organizational culture is the set of shared values, beliefs, and norms that influence the way people think, feel, and behave in an organization. It affects the project management style, communication, stakeholder engagement, and change management. By assessing the organizational culture, the project manager can identify the potential barriers and enablers for agile transformation, and plan appropriate strategies to address them. For example, the project manager can provide training, coaching, mentoring, and feedback to the functional groups to help them understand and embrace the agile values and principles. Circulating the project charter (option A) is a good practice, but it does not ensure that the functional groups are prepared and supportive of the agile approaches.
Determining the level of maturity of the employees (option C) is a useful input, but it does not capture the whole picture of the organizational culture. Communicating the project schedule (option D) is also important, but it does not address the underlying reasons for the pushback from the functional groups. References:
* PMBOK Guide, 6th edition, page 30-31, section 2.2.2 Organizational Culture
* [Agile Practice Guide], page 16-17, section 2.1.2 Organizational Culture
* PMP Exam Prep, 10th edition, page 435, question 435, answer and explanation