Synonym of SPORADIC

Answer: Option C

Genuine : truly what something is said to be; authentic.
Accidental : happening by chance, unintentionally, or unexpectedly.
Irregular : not even or balanced in shape or arrangement.
Instinctive : relating to or prompted by instinct; done without conscious thought.
Sporadic : occurring at irregular intervals or only in a few places; scattered or isolated.

Synonym of Sporadic is Irregular