https://docs.microsoft.com/en-us/azure/virtual-network/security-overview

Section: Understand Core Azure Services
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

Section: Understand Cloud Concepts
Explanation:
With the public cloud, you get pay-as-you-go pricing - you pay only for what you use, no CapEx costs.
With the public cloud, you have self-service management. You are responsible for the deployment and configuration of the cloud resources such as virtual machines or web sites. The underlying hardware that hosts the cloud resources is managed by the cloud provider.
Incorrect Answers:
A: You don't have dedicated hardware. The underlying hardware is shared so you could have multiple customers using cloud resources hosted on the same physical hardware.
B: Connections to the public cloud are secure.
C: Storage is not limited. You can have as much storage as you like.
References:
https://docs.microsoft.com/en-gb/learn/modules/principles-cloud-computing/4-cloud-deployment-models