Correct Option: B. Supply decreases Detailed Explanation: When we talk about the supply of a good, we are referring to the quantity of that good that producers are willing and able to sell at various prices, all else being equal. The relationship between production costs and supply is crucial in understanding how market dynamics work.

1. Understanding Production Costs:
2. Production costs include all expenses incurred in the process of producing a good or service. This can include costs for raw materials, labor, machinery, and overheads. When production costs increase, it means that it becomes more expensive for producers to create the same quantity of goods.
3. Impact on Supply:
4. When production costs rise, producers face a higher financial burden. To maintain profitability, they may need to either raise prices or reduce the quantity they are willing to supply at existing prices.
5. If the price of the good does not increase to cover the higher costs, producers will find it less attractive to produce the same quantity as before. Consequently, they will supply less of the good at the previous price levels, leading to a decrease in supply.
6. Graphical Representation:
7. If we were to draw a supply curve on a graph, the supply curve typically slopes upwards from left to right, indicating that as prices increase, the quantity supplied also increases.
8. An increase in production costs shifts the supply curve to the left. This leftward shift indicates that at every price level, the quantity supplied is now lower than it was before the increase in costs.
9. Market Equilibrium:
10. In a market, the equilibrium price is determined by the intersection of the supply and demand curves. If the supply curve shifts left due to increased production costs, the new equilibrium will be at a higher price and a lower quantity sold, assuming demand remains constant.

Why Other Options Are Incorrect:

• Option A: Supply increases: This option is incorrect because an increase in production costs does not incentivize producers to supply more; rather, it discourages them from supplying the same quantity, leading to a decrease in supply.
• Option C: Supply remains unchanged: This option is also incorrect. If production costs rise, it is unlikely that producers will continue to supply the same quantity without adjusting their prices or reducing output. The very nature of increased costs implies a change in the supply dynamics.
• Option D: Supply becomes perfectly elastic: This option is incorrect as well. Perfectly elastic supply means that producers are willing to supply any quantity at a specific price. An increase in production costs would not lead to a perfectly elastic supply; instead, it would lead to a decrease in supply, as producers would not be able to maintain the same quantity supplied at previous price levels.

Summary of Key Points:

• An increase in production costs leads to a decrease in supply, as producers are less willing to supply the same quantity at existing prices.
• The supply curve shifts to the left, indicating a lower quantity supplied at every price level.
• The new market equilibrium will typically result in a higher price and lower quantity sold.
• Understanding the relationship between production costs and supply is crucial for analyzing market behavior.

This comprehensive understanding of how production costs affect supply will help you grasp the fundamental concepts in economics and prepare effectively for your exams.