Counter offer and Request from information

Hello Sir mike,

Kindly help with the question below

“I’m very interested by your offer, and I would like to accept it, but would you be prepared to give 5% discount for immediate payment?”

The started response to an offer can be seen as

A- counter offer
B- mere request for information
C- possibly an acceptance.

I understand according to your lecture on contract law that a counter offer occur when an offeree change any element of original term, could requesting for 5% discount be seen as changing original term or mere request. I will be grateful if you can throw light on this.

Thanks.