You are the IT administrator in a company with a Microsoft 365 E5 subscription. You are responsible for security in your organization and have deployed Microsoft Cloud App Security. Your company is concerned with the presence of shadow IT, and you have been tasked with overseeing the discovery of shadow IT. 
Select three valid data sources that can be used for discovering Shadow IT:

Answer options:

A.Azure Activity Log
B.Azure Sentinel
C.Log Collector
D.Defender ATP
E.Secure Web Gateway
F.Application Insight

Correct Answers: C, D and E 
You can install a log collector for continuous monitoring, A log collector provides insight to Microsoft Cloud App Security. 
You can also integrate a Secure Web Gateway with Microsoft Cloud App Security. This will replace the need to install log collectors on your network endpoints. 
You can also integrate Microsoft Cloud App Security with Defender ATP. This will provide you with tools to discover cloud apps accessed from managed Windows 10 machines.
Option A is incorrect. This is where you see subscription level events in your tenant
Option B is incorrect. Azure Sentinel is a cloud-native security solution.
Option F is incorrect. Application Insights is an application performance management which lets you monitor your live applications.
Reference: 
To know more about discovering shadow IT, please refer to the link below: 

https://www.microsoft.com/security/blog/2019/03/26/step-7-discover-shadow-it-and-take-control-of-your-cloud-apps-top-10-actions-to-secure-your-environment/