Explanation:

You can restrict traffic to multiple virtual networks with a single Azure firewall.
Azure Firewall is a managed, cloud-based network security service that protects your Azure Virtual Network resources. It's a fully stateful firewall as a service with built-in high availability and unrestricted cloud scalability.
You can centrally create, enforce, and log application and network connectivity policies across subscriptions and virtual networks. Azure Firewall uses a static public IP address for your virtual network resources allowing outside firewalls to identify traffic originating from your virtual network.
References:
https://docs.microsoft.com/en-us/azure/firewall/overview

Explanation

The advanced monitoring capabilities in Security Center lets you track and manage compliance and governance over time. The overall compliance provides you with a measure of how much your subscriptions are compliant with policies associated with your workload.
Reference:
https://docs.microsoft.com/en-us/azure/security-center/security-center-intro