Final answer:
The alternative to exchange in a market economy is to be self-sufficient, which is less efficient than market trade facilitated by currency. The law of supply states that producers will offer more of a good as its price increases.
Step-by-step explanation:
The alternative to exchange is to be self-sufficient. In a free-market economy, the ideal scenario is where producers and consumers negotiate terms that benefit both parties, facilitated by the use of a common currency. The law of supply suggests that as the price of a good increases, producers are willing to offer more of it, all else being equal. On the other hand, without exchange, individuals must be self-sufficient, producing all they need, which is often less efficient due to the lack of specialization.