You have an Azure subscription that contains 10 virtual machines and the resources shown in the following table.

You need to ensure that Bastion1 can support 100 concurrent SSH users. The solution must minimize administrative effort.
What should you do first?

A. Resize the subnet of Bastion1 B. Configure host scaling. C. Create a network security group (NSG) D. Upgrade Bastion1 to the Standard SKU