Antonym of MITIGATE

Answer: Option C

Mitigate : make (something bad) less severe, serious, or painful.
Stagnate : (of water or air) cease to flow or move; become stagnant.
Suffer : experience or be subjected to (something bad or unpleasant).
Aggravate : make (a problem, injury, or offence) worse or more serious.
Instigate : incite someone to do something, especially something bad.

Antonym of Mitigate is Aggravate