The council appointed a … committee to look into the matter.

Analyze the question: We need the correct form of a compound modifier placed before the noun "committee."

Concept: When a number and a noun combine to describe another noun, they form a compound adjective joined by a hyphen. In this structure the noun stays singular, even when the number is more than one.

• a ten-year plan (not "ten-years")
• a two-hour lecture
• a five-man committee

Checking each option:

• A. five-men: The noun "men" is plural, which is wrong in a compound adjective.
• B. five-men's: This adds a plural possessive, which is wrong because the committee doesn't belong to the men.
• C. five man: The noun is singular, which is correct. The hyphen is missing, so the standard form is "five-man," but this is the only option with the correct singular structure.
• D. five-man's: This adds a possessive "'s," which is not needed because there is no ownership.

Conclusion: The correct form is "five-man committee." Option C is the only one with the singular "man," so it is the best choice.

Tip: When a number and a noun describe another noun, keep the noun singular and don't add 's. Think "a five-year-old child," not "a five-years-old child."