You have installed AD Connect on a Domain controller and need to perform troubleshooting by inspecting the generated AD Connect events. Where should you look?

Answer options:

A.The System event logs.
B.Application event logs.
C.The Security event logs.
D.The Windows Azure event logs

Correct Answer: B 
All directory synchronization logging is viewable in Event Viewer in the Application event logs: 
Open Event Viewer. 
Expand Windows Logs, and then expand Application. 
In the Actions pane, select Filter Current Log. 
In the Event sources box, select the Directory Synchronization check box. 

Option A is incorrect. System event logs displays system events.
Option C is incorrect. The security event logs display events involving server security.
Option D is incorrect. These logs are generated for Log analytic agents installed on the server.
Reference: 
To know more about troubleshooting Azure Directory sync, please refer to the link below: 

https://docs.microsoft.com/en-us/troubleshoot/azure/active-directory/installation-configuration-wizard-errors