The correct answer is C - A momentum investment strategy.

Why momentum is most destabilizing:

• Momentum strategy: Involves buying assets that have recently performed well and selling those that have performed poorly
• This creates positive feedback loops where rising prices attract more buyers, pushing prices further from fundamental values
• Momentum can amplify price bubbles and crashes as trends become self-reinforcing

Comparison with other strategies:

• Value strategy (A): Typically stabilizes prices by buying undervalued assets and selling overvalued ones (negative feedback)
• Size strategy (B): Focuses on company size characteristics and is generally less destabilizing than momentum
• D: Incorrect - While value strategies can be stabilizing, momentum strategies are known to be destabilizing

Momentum investing can lead to herding behavior and excessive price volatility as investors chase recent performance trends rather than fundamental values.