What signifies an increase in supply or demand on a graph?

An increase in supply or demand on a graph is represented by a shift of the curve to the right. When demand increases, consumers are willing to purchase more of a good or service at every price level, resulting in a rightward shift of the demand curve. Similarly, if supply increases, producers are willing to sell more of a good or service at every price level, causing the supply curve to also shift to the right.

This rightward shift indicates a higher quantity of goods available in the market (for supply) or a higher willingness to purchase (for demand), effectively reflecting the increased market activity. The fundamental concept here relates to the interactions between consumers and producers; when either group shows greater willingness to engage in transactions, it is visualized through this rightward movement on a graph, marking a shift in the equilibrium point where supply and demand meet.

The other options describe movements that are not indicative of an increase. A leftward shift would imply a decrease in either supply or demand, while rotating or flattening a curve does not accurately represent an increase in quantity demanded or supplied across different price points.