Final answer:
Marginal utility analysis suggests that higher prices reduce the quantity demanded, resulting in a downward sloped demand curve, reflecting changes in consumer utility and preferences. option a.
Step-by-step explanation:
Marginal utility analysis indicates that, all else being equal, an increase in the price of a good prompts each consumer to diminish the quantity of the good. Consequently, this implies a downward sloped demand curve. When the price of a good rises, consumers' budget constraints shift to the left, and they reach lower indifference curves, indicating a reduced level of utility. Likewise, when the price decreases, the opportunity set shifts right, and higher indifference curves are reached, suggesting an increased level of utility. These shifts in budget constraints reflect changes in quantity demanded due to price changes, adhering to personal preferences and the fundamental principles of demand.