Final answer:
The positive slope of the supply curve means that as the price increases, producers are incentivized to supply a larger quantity of goods, which is explained by option (d). The correct answer is option d.
Step-by-step explanation:
The student has asked about the meaning of the positive slope of the supply curve. The supply curve typically slopes upwards from left to right, signifying that as the price of a good increases, producers are willing and able to produce and supply more of it. Let's consider the options provided to understand this concept better.
Option (a) suggests that as production increases, the total cost of production falls, which is not necessarily true; in fact, costs often increase with increased production due to factors such as the need for more materials, labor, and possibly less efficient use of resources as firms push beyond their capacity.
Option (b), which posits that an increase in input prices increases supply, is incorrect because usually increased input costs would decrease supply, as it becomes more expensive to produce goods.
Option (c) claims that the quantity supplied of most goods and services increases over time. While this can be true, it's more of a general statement about economic growth rather than an explanation of the positive slope of the supply curve.
Finally, option (d) states that an increase in price gives producers an incentive to supply a larger quantity, which is a correct assertion and in line with the basic principles of supply and demand. When prices rise, firms stand to make more profit by selling goods at a higher price, thus they are incentivized to produce more.
The correct option that explains the positive slope of the supply curve is (d): an increase in price gives producers an incentive to supply a larger quantity.