Explanation:
Box 1: No
Not all Azure regions support availability zones.
Box 2: No
Regions that support availability zones support Linux virtual machines.
Box 3: Yes
Availability Zones is a high-availability offering that protects your applications and data from datacenter failures. Availability Zones are unique physical locations within an Azure region. Each zone is made up of one or more datacenters equipped with independent power, cooling, and networking. To ensure resiliency, there's a minimum of three separate zones in all enabled regions. The physical separation of Availability Zones within a region protects applications and data from datacenter failures. Zone-redundant services replicate your applications and data across Availability Zones to protect from single-points-of-failure. With Availability Zones, Azure offers industry best 99.99% VM uptime SLA.
References:
https://docs.microsoft.com/en-gb/azure/availability-zones/az-overview

Fault tolerance is the ability of a system to continue to function in the event of a failure of some of its components.
In this question, you could have servers that are replicated across datacenters.
Availability zones expand the level of control you have to maintain the availability of the applications and data on your VMs. Availability Zones are unique physical locations within an Azure region. Each zone is made up of one or more datacenters equipped with independent power, cooling, and networking. To ensure resiliency, there are a minimum of three separate zones in all enabled regions. The physical separation of Availability Zones within a region protects applications and data from datacenter failures.
With Availability Zones, Azure offers industry best 99.99% VM uptime SLA. By architecting your solutions to use replicated VMs in zones, you can protect your applications and data from the loss of a datacenter. If one zone is compromised, then replicated apps and data are instantly available in another zone.
https://docs.microsoft.com/en-us/azure/virtual-machines/windows/manage-availability

Explanation:
References:
https://buildazure.com/2016/08/18/powershell-now-open-source-and-cross-platform-linux-macos-windows/

Section: Understand Core Azure Services
Explanation:
In the Azure virtual machines page in the Azure portal, there is a named Maintenance Status. This column will display service issues that could affect your virtual machine. A service failure is rare but host server maintenance that could affect your virtual machines is more common.
Azure periodically updates its platform to improve the reliability, performance, and security of the host infrastructure for virtual machines. The purpose of these updates ranges from patching software components in the hosting environment to upgrading networking components or decommissioning hardware.
References:
https://docs.microsoft.com/en-us/azure/virtual-machines/maintenance-and-updates