Which Azure service provides a set of tools for developing AI solutions involving neural networks?

Azure Machine Learning is specifically designed as a comprehensive platform for building, training, deploying, and managing machine learning models, including those that utilize neural networks. It provides a range of tools and features that facilitate the development of AI solutions, such as automated machine learning, data labeling, and support for various deep learning frameworks like TensorFlow and PyTorch. Users can leverage Azure Machine Learning to create sophisticated AI applications that can scale and integrate seamlessly with other Azure services.

The other options, while valuable Azure services, do not focus primarily on the development of AI and neural network solutions. Azure Data Factory is primarily for data integration and transformation tasks, Azure Functions is a serverless compute service that allows for running event-driven code, and Azure DevOps provides development collaboration tools and services for software development, rather than specifically addressing AI model development. Therefore, Azure Machine Learning is undoubtedly the most suitable choice for developing AI solutions involving neural networks.