Synonym of REBATE

Answer: Option C

Commission : an instruction, command, or role given to a person or group.
Interest : the feeling of wanting to know or learn about something or someone.
Discount : a deduction from the usual cost of something.
Gift : a thing given willingly to someone without payment; a present.
Rebate : a deduction or discount on a sum of money due.

Synonym of Rebate is Discount