正解:C
In the context of a global program with distributed teams, videoconferencing is often the most effective way for project teams to interact in their meetings. Videoconferencing allows for real-time communication, visual cues, and can facilitate better understanding and collaboration among team members. While phone conversations, encrypted emails, and chat conversations can also be used, they may not provide the same level of interaction and engagement as videoconferencing. It's important to note that the choice of communication method should also consider the nature of the meeting, the preferences of the team members, and the information security requirements of the project. References:
https://www.projectmanager.com/blog/project-meetings-for-your-team
https://www.predictiveindex.com/blog/eight-tips-on-how-to-best-interact-with-your-team-members/