Your company is leveraging Azure Monitor to oversee its cloud infrastructure and applications. As part of enhancing operational efficiency, you are tasked with configuring a feature within Azure Monitor that not only allows for the definition of alert rules based on a variety of signals such as metrics, logs, and activity logs but also enables the customization of alert severity levels and the selection of appropriate notification channels. This ensures that the right personnel are alerted promptly in case of critical events. Given the company's emphasis on cost-effectiveness, scalability, and compliance with internal policies, which of the following Azure Monitor features best meets these requirements? (Choose one option)