Which of the following are characteristics of Data Collection Rules (DCRs) in Azure Monitor?

Data Collection Rules (DCRs) in Azure Monitor are essential for managing data collection in a structured and efficient manner. The correct answer highlights that DCRs specify what data is collected, how to transform it, and where to send it. This encapsulates the primary purpose of DCRs, which is to provide a customizable framework that allows users to define the data sources and the specific parameters for processing that data.

By detailing the data sources involved, transformation processes that may be needed to format or filter the data, and the destinations where the data should be sent, DCRs serve as a crucial tool for ensuring that the right data enters the Azure Monitor ecosystem in the desired format and location. This flexibility is vital for optimizing monitoring and analytics processes.

The other choices do not capture the comprehensive nature of DCRs. For instance, defining alert thresholds pertains more to alert rules rather than the collection rules themselves. The notion that DCRs are only applicable to virtual machines limits their scope, as they can be utilized across various Azure resources. Lastly, while Azure CLI is a powerful tool for resource management, DCRs can also be created and managed through the Azure portal, SDKs, and other methods, making them not exclusive to CLI.