Answer:
voluntary exchange that makes both the consumer and producer better off.
Explanation:
The consumer will purchase at a price lower or equal to he is willing to pay for the good (we assume a rational person will not urchase above their willingless to do so) Thus, either has a surplus or the price is fair
The producer as well, only trades for a price above their expect to sale or that amount. Therefore it has a surplus or received what it expect.
We have determinated there is no winner or losser in trade as both parites agree voluntary without coercion.
