The correct answer is: B. Flatter in long run
The supply curve is a graph that shows the relationship between the price of a good and the quantity of that good that producers are willing and able to supply. In the short run, firms have some fixed costs, so they can only increase production by a limited amount in response to an increase in price. This means that the supply curve is relatively steep in the short run.
In the long run, firms have time to adjust all of their costs, so they can increase production by a much larger amount in response to an increase in price. This means that the supply curve is much flatter in the long run.
Here is a diagram that illustrates the difference between the short-run and long-run supply curves:
[Diagram of a short-run and long-run supply curve]
The short-run supply curve is represented by the line S1, and the long-run supply curve is represented by the line S2. As you can see, the long-run supply curve is flatter than the short-run supply curve. This is because firms can increase production by a much larger amount in the long run than they can in the short run.
I hope this explanation is helpful! Please let me know if you have any other questions.