Final answer:
The law of supply establishes a direct relationship between the price of the good and the quantity supplied, where a higher price leads to a higher quantity supplied, and a lower price leads to a lower quantity supplied. Thus, the option 4 is the correct answer.
Step-by-step explanation:
According to the law of supply, there is a direct relationship between the quantity supplied and the price of the good. This law posits a common relationship that a higher price leads to a greater quantity supplied and vice versa. The other options mentioned, such as the number of sellers, costs of resources, and technology, can affect supply but are not directly tied to the immediate principle of the law of supply.
The law of supply is crucial in economics because it helps explain producer behavior in the market. If prices increase, profit-seeking firms are encouraged to supply more of that good or service. In contrast, if prices decrease, the quantity supplied will typically reduce because it might not be as profitable for firms to produce at the lower price.