Explanation:
Box1 : 10.0.0.0/16
Address prefix in networking refer to the destination IP address range. In this scenario, destination is Vnet1 , hence Address prefix will be the address space of Vnet1.
Box 2 : Virtual appliance
Next hop gets the next hop type and IP address of a packet from a specific VM and NIC. Knowing the next hop helps you determine if traffic is being directed to the intended destination, or whether the traffic is being sent nowhere Next Hop --> VM1 --> Virtual Appliance (You can specify IP address of VM 1 when configuring next hop as virtual appliance) Box 3 : GatewaySubnet In the scenario it is asked for all the inbound traffic to Vnet1. Inbound traffic is flowing through SubnetGW. You need to route all inbound traffic from the VPN gateway to VNet1 through VM1.So its traffic from Gateway subnet only.
Reference:
https://docs.microsoft.com/en-us/azure/virtual-network/manage-route-table#create-a-route-table
https://docs.microsoft.com/en-us/azure/network-watcher/network-watcher-next-hop-overview

Explanation

We cannot just move a virtual machine between networks. What we need to do is identify the disk used by the VM, delete the VM itself while retaining the disk, and recreate the VM in the target virtual network and then attach the original disk to it.
First action: Delete VM1
Second action: Create a new virtual machine
Reference:
https://docs.microsoft.com/en-us/archive/blogs/canitpro/step-by-step-move-a-vm-to-a-different-vnet-on-azure
https://4sysops.com/archives/move-an-azure-vm-to-another-virtual-network-vnet/#migrate-an-azure-vmbetween

Explanation
Cost analysis: Correct Option
In cost analysis blade of Azure, you can see all the detail for custom time span. You can use this to determine expenditure of last few day, weeks, and month. Below options are available in Cost analysis blade for filtering information by time span: last 7 days, last 30 days, and custom date range. Choosing the first option (last 7 days) auditors can view the costs by time span.
Cost analysis shows data for the current month by default. Use the date selector to switch to common date ranges quickly. Examples include the last seven days, the last month, the current year, or a custom date range.
Pay-as-you-go subscriptions also include date ranges based on your billing period, which isn't bound to the calendar month, like the current billing period or last invoice. Use the <PREVIOUS and NEXT> links at the top of the menu to jump to the previous or next period, respectively. For example, <PREVIOUS will switch from the Last 7 days to 8-14 days ago or 15-21 days ago.

Invoice: Incorrect Option
Invoices can only be used for past billing periods not for current billing period, i.e. if your requirement is to know the last week's cost then that also not filled by invoices because Azure generates invoice at the end of the month. Even though Invoices have custom timespan, but when you put in dates for a week, the pane would be empty. Below is from Microsoft document:

Resource Provider: Incorrect Option
When deploying resources, you frequently need to retrieve information about the resource providers and types.
For example, if you want to store keys and secrets, you work with the Microsoft.KeyVault resource provider.
This resource provider offers a resource type called vaults for creating the key vault. This is not useful for reviewing all Azure costs from the past week which is required for audit.
Payment method: Incorrect Option
Payment methods is not useful for reviewing all Azure costs from the past week which is required for audit.
Reference:
https://docs.microsoft.com/en-us/azure/cost-management-billing/costs/quick-acm-cost-analysis
https://docs.microsoft.com/en-us/azure/cost-management-billing/manage/download-azure-invoice-daily-usage-da

Reference:
https://docs.microsoft.com/en-us/azure/service-bus-messaging/message-expiration
https://docs.microsoft.com/en-us/azure/service-bus-messaging/message-transfers-locks-settlement

Explanation

Box 1: Cloud-init.txt
Cloud-init.txt is used to customize a Linux VM on first boot up. It can be used to install packages and write files, or to configure users and security. No additional steps or agents are required to apply your configuration.
Box 2: The az vm create command
Once Cloud-init.txt has been created, you can deploy the VM with az vm create cmdlet, sing the --customdata parameter to provide the full path to the cloud-init.txt file.
References:
https://docs.microsoft.com/en-us/azure/virtual-machines/linux/tutorial-automate-vm-deployment