Correct Answer:
C. Illicit
This question checks your knowledge of synonyms. The word "unlawful" refers to something that is illegal, prohibited, or contrary to the law. A synonym should carry the same meaning.
Among the options, "Illicit" is the correct synonym because it means illegal or forbidden by law. The other options—legal, fair, and just—have meanings that differ from or are opposite to unlawful.
- Unlawful: Not permitted by law.
- Synonym: Illicit.
- Antonym: Legal.
Therefore, the correct answer is: "Illicit".