What advancement in AI did Google's AlphaGo represent?

Google's AlphaGo represented a significant advancement in AI by achieving success in defeating a human Go champion. This event marked a milestone in AI development and illustrated the ability of AI systems to handle complex tasks that were traditionally thought to require human intuition and strategy.

AlphaGo's victory over a world-class player showcased the system's capability to learn and improve its performance through deep learning and reinforcement learning techniques. It demonstrated AI's potential not just in narrowly defined games, but also in complex scenarios requiring strategic thinking and planning, which is far more sophisticated than the challenges presented by many other games like chess.

The other options do not accurately reflect the significance of AlphaGo's achievements. For example, the notion of a breach in ethical AI practices does not apply here as AlphaGo was developed under stringent academic and ethical guidelines. Similarly, the introduction of expert systems is not relevant because AlphaGo was based on advanced machine learning techniques rather than traditional rule-based systems. Finally, decreased funding for AI research is contrary to the trend seen as a result of advancements like AlphaGo, which generally spurred interest and investment in AI technologies.