Final answer:
The NSC is composed of a group of people who meet irregularly and on short notice, including the national security advisor, senior-level staff from multiple foreign policy agencies, and important figures in the intelligence community and military.
Step-by-step explanation:
The NSC (National Security Council) is composed of a group of people who meet irregularly and on short notice. The NSC members include the national security advisor, who is the president's top foreign policy advisor, as well as senior-level staff from multiple foreign policy agencies. Additionally, the director of the Central Intelligence Agency (CIA), the director of national intelligence, and the Joint Chiefs of Staff are among the important members of the NSC.