Explanation:

According to the Microsoft Azure AI Fundamentals (AI-900) official study materials and the Microsoft Learn module: "Describe features of common AI workloads", conversational AI solutions like chatbots can be created using various methods-not only through custom code. Azure provides both no-code/low-code and developer-focused approaches. For instance, users can design chatbots using Power Virtual Agents, which requires no programming knowledge, or they can use Azure Bot Service with the Bot Framework SDK for fully customized scenarios. Hence, the statement "Chatbots can only be built by using custom code" is False (No) because Azure supports multiple levels of technical involvement for building bots.
The second statement is True (Yes) because the Azure Bot Service is designed specifically to host, manage, and connect conversational bots to users across different channels. Microsoft Learn explicitly explains that the service provides integrated hosting, connection management, and telemetry for bots built using the Bot Framework or Power Virtual Agents. It acts as the foundation for deploying, scaling, and managing chatbot workloads in Azure.
The third statement is also True (Yes) because Azure Bot Service supports integration with Microsoft Teams, among many other channels such as Skype, Facebook Messenger, Slack, and web chat. Microsoft documentation states that Azure-hosted bots can communicate directly with Teams users through the Teams channel, enabling intelligent virtual assistants within the Teams environment.