Synonym of INFREQUENT

Answer: Option C

Never : at no time in the past or future; not ever.
Usual : habitually or typically occurring or done; customary.
Rare : (of an event, situation, or condition) not occurring very often.
Frequent : occurring or done many times at short intervals.
Infrequent : not occurring often; rare.

Synonym of Infrequent is Rare