Why do shifts in marginal cost within a certain range not affect price and quantity in a kinked-demand scenario?

• A. Because the kink in the demand curve creates a range of marginal costs that do not alter equilibrium.
• B. Because demand is perfectly elastic within this range.
• C. Because firms are unable to change production levels.
• D. Because marginal cost is irrelevant in oligopolistic markets.

Answer: (A)