This is a cloze test question requiring the selection of the word that correctly fills gap 6 in the passage. Based on the pattern of vocabulary across the surrounding gaps (which include terms such as peace, security, member, charter, and sanctions), the passage concerns the United Nations Security Council and its role in maintaining international order.
The correct word for this gap is Council. The phrase "Security Council" is the formal name of one of the six principal organs of the United Nations, and it is the body primarily responsible for maintaining international peace and security. No other option produces a recognised institutional name in this context:
"Security Unit" is not a standard name for any UN organ.
"Security Department" does not name the body described.
"Security Committee" is not the correct designation; while the UN has various committees, the principal organ responsible for peace and security is specifically called the Security Council.
