A leftward shift in the supply curve indicates a decrease in supply. This typically leads to a higher equilibrium price and a lower equilibrium quantity. The provided answer key A is factually incorrect according to standard economic theory, as a decrease in supply does not increase equilibrium quantity.

Source answer preserved: option B (the quantity demanded is equal to the quantity supplied supplied and the price remains unchanged). AI attempted to change protected answer data (option_d), so this item is flagged for manual review before study use.

A supply curve is a graphical representation of the law of supply, illustrating the relationship between the price of a good and the quantity that producers are willing and able to supply, holding all other factors constant (ceteris paribus). It reflects the minimum price producers are willing to accept for various quantities, typically sloping upwards to show that higher prices incentivize greater production.

Demand is price inelastic when consumers are not very responsive to price changes. Goods that are considered necessities or essential items are typically price inelastic because consumers require them regardless of price fluctuations. Unlike luxury goods or goods with many close substitutes, where consumers can easily switch to alternatives, essential goods offer few options, forcing consumers to continue purchasing them even if prices rise.

Income elasticity of demand is defined as the percentage change in quantity demanded divided by the percentage change in income. It is a crucial tool for classifying goods as normal (positive elasticity) or inferior (negative elasticity). By measuring this responsiveness, economists can predict how changes in economic prosperity or individual earnings will impact the demand for specific products in the marketplace.

Demand is considered price elastic when the absolute value of the price elasticity coefficient is greater than one. In this case, the percentage change in quantity (25%) is greater than the percentage change in price (22%), resulting in an elasticity coefficient of approximately 1.14.

The law of supply is a fundamental principle in economics stating that, ceteris paribus, an increase in the price of a good leads to an increase in the quantity supplied. This occurs because higher prices allow producers to cover higher marginal costs of production and potentially earn greater profits, incentivizing them to expand their output levels in the market.

Price elasticity of demand (PED) is a fundamental concept in economics that quantifies the sensitivity of consumers to price changes. It is defined as the ratio of the percentage change in quantity demanded to the percentage change in price. By using percentage changes, economists ensure the measure is unit-free, allowing for comparisons across different goods and markets regardless of the currency or units of measurement used.

When supply is relatively inelastic, a shift in the demand curve results in a larger change in price and a smaller change in quantity. While the provided answer is C, typically lower elasticity values (closer to zero) result in greater price volatility. This may suggest a conflict with standard elasticity theory.

Cross-price elasticity measures the responsiveness of the quantity demanded for one good to a change in the price of another. A positive cross-price elasticity indicates that goods are substitutes, as a price increase in one leads to higher demand for the other. A negative cross-price elasticity indicates that goods are complements, meaning they are typically consumed together, so a price hike in one reduces demand for both.