A person who maliciously destroys by fire

A Antagonist
B Activist
C Terrorist
D Incendiary

Correct Answer: Incendiary

One word substitute is Incendiary.

Antagonist: a person who actively opposes or is hostile to someone or something; an adversary.
Activist: a person who campaigns to bring about political or social change.
Terrorist: a person who uses unlawful violence and intimidation, especially against civilians, in the pursuit of political aims.
Incendiary: a person who starts fires.

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