You need to configure a host name for WebApp2.
What should you do first?
A . In Azure AD, add contoso.com as a custom domain name
B . In the public DNS zone of contoso.onmicrosoft.com, add an NS record
C . In Azure AD, add webapp2.azurewebsites.net as a custom domain name
D . In the public DNS zone of contoso.com, add a CNAME record
Scenario: Ensure that webapp2.azurewebsites.net can be accessed by using the name app2.contoso.com
When you create a Cloud Service, Azure assigns it to a subdomain of cloudapp.net. For example, if your Cloud Service is named "contoso", your users will be able to access your application on a URL like http:// contoso.cloudapp.net. Azure also assigns a virtual IP address.
However, you can also expose your application on your own domain name, such as contoso.com.