Explanation

Let's analyze each option:

A. Investor sentiment changes from enthusiasm to despair - This would likely cause a significant stock price change as it represents a major shift in market psychology and risk appetite.

B. The central bank raises interest rates in line with expectations - Since this is already anticipated by the market, the impact would be minimal as it's already priced in.

C. The company confirms widely anticipated information about its new project - Again, since this information was widely anticipated, the confirmation would not significantly move the stock price.

Correct Answer: A - Changes in investor sentiment represent new, unexpected information that can dramatically affect stock prices, while anticipated events are already reflected in current prices.