James says he would like to buy Mike's motorbike for $$3,000.$ Mike responds by saying he would accept $$4,000$ given all the work he has put into it$.$ James says $"$Ok$.$ I'll give that. Here's $$2,000$ now, and I'll pay the balance in two instalments."

Group of answer choices

This is an acceptance

This is not a contract

This is a contract

This is an offer