Which of the following is a company associated with Google's investigation into AI and Machine Learning?

DeepMind is the correct association when discussing Google's investigation into AI and Machine Learning. Acquired by Google in 2014, DeepMind is renowned for its advancements in artificial intelligence technologies, particularly in the realm of neural networks and reinforcement learning. Their work includes breakthroughs like the development of AlphaGo, which famously defeated a world champion in the complex game of Go. This demonstrates not only their innovative approaches to AI but also showcases how Google leverages DeepMind’s research to enhance its own machine learning capabilities.

The other options represent important products or divisions within Google, but they are not primarily focused on pioneering AI and machine learning research. Android is a mobile operating system, YouTube is a video-sharing platform, and Chrome is a web browser. While all these products benefit from machine learning improvements, they are not dedicated AI research entities like DeepMind.