The process during which both the salesperson and the prospect offer special concessions in an attempt to arrive at a sales agreement is known as

Negotiation

Explanation: Negotiation refers to the exchange of offers for various small different deals made with the intent to fix the ultimate final agreement. The offering in negotiation process is usually done in a verbal manner. In a negotiation process both the parties tries to understand the expectation of other party and make changes to the offer as seem required.

Hence, we can conclude that the right answer is negotiation.

answer; no individual buyer or seller has any significant impact on the market price;