You manage a cloud service that has a web role named fabWeb. You create a virtual network
named fabVNet that has two subnets defined as Web and Apps. You need to be able to deploy
fabWeb into the Web subnet. What should you do?

A.
Modify the service definition (csdef) for the cloud service.

B.
Run the Set-AzureSubnet PowerShell cmdlet.

C.
Run the Set-AzureVNetConfig PowerShell cmdlet.

D.
Modify the network configuration file.

E.
Modify the service configuration (cscfg) for the fabWeb web role.

Explanation:
To deploy a cloud service into the Apps subnet in the virtual network, you need to add an element
to the cloud service configuration file with settings identify the Apps subnet in the virtual network.
When the cloud service with this configuration is deployed, Azure will identify the network
configuration and provision the virtual machine instances in the Apps subnet.
https://outhereinthefield.wordpress.com/2014/05/23/adding-a-windows-azure-cloud-service-tovirtual-network/