Final answer:
The Foreign Service Officer should first establish a comfortable and open atmosphere for Peace Corps volunteer introductions before sharing detailed cultural information or personal experiences.
Step-by-step explanation:
When a Foreign Service Officer (FSO) is facilitating an introductory meeting of Peace Corps volunteers, the first action they should take is C) Establish a comfortable and open atmosphere for introductions. Creating this atmosphere is crucial for setting a positive tone for the meeting and ensuring that volunteers feel welcome and valued. It also helps facilitate open communication, which will be important as volunteers begin their humanitarian work. Once a comfortable environment is established, the FSO can then provide a detailed overview of the host country's culture, share personal anecdotes, and distribute informational pamphlets about the Peace Corps as follow-up activities.