Antonym of MODERATE

Answer: Option C

Moderate : a person who holds moderate views, especially in politics.
Radical : (especially of change or action) relating to or affecting the fundamental nature of something; far-reaching or thorough.
Revolutionary : involving or causing a complete or dramatic change.
Nihilist : a person who believes that life is meaningless and rejects all religious and moral principles.
Anarchist : a person who believes in or tries to bring about anarchy.

Antonym of Moderate is Nihilist