Final answer:
The threats to companies that have successfully implemented cost leadership strategies and product differentiation strategies are both dramatic technological change and changes in consumer tastes.
Step-by-step explanation:
The correct answer is C. both. Both dramatic technological change and changes in consumer tastes can pose threats to companies that have successfully implemented cost leadership strategies as well as companies that have successfully implemented product differentiation strategies.
Dramatic technological change can render a company's cost leadership strategy obsolete, as new technologies may allow competitors to produce products at lower costs or offer superior products at lower prices. Similarly, changes in consumer tastes can undermine a company's product differentiation strategy, as shifting preferences may make the company's unique features or attributes less appealing or desirable.
Therefore, companies that have successfully implemented either cost leadership or product differentiation strategies need to be aware of these potential threats and adapt to the changing technological landscape and consumer preferences to maintain their competitive advantage.