You integrated SonarCloud with the Azure DevOps CI pipeline. In a month, you want to see how many times SonarCloud was used. 
Where can you find this information?

Answer options:

A.Pipelines settings
B.Service hooks
C.Service connections
D.Agent pools

Correct Answer: C 
Azure DevOps allows users to connect to the outside services for task execution during the pipeline run. Such tasks can be a connection to the Azure subscription, or Jenkins service for CI of the Git repos, or to SonarCloud for automatic code quality and vulnerability review. To connect to these and other services, Azure DevOps provides
Service connections. 
You can create a new service connection by selecting the Service connections (Number 2) menu item on the Project Settings (Number 1) blade. You need to choose a service or a connection type from the list for the new connection and provide connection information details. After the connection is successfully created and external task execution is added to the pipeline, you can see the connection’s usage history when you open the link from the list of the Service connections. The usage history for each pipeline run will be on the Usage history tab (Number 3).

Option A is incorrect because the Pipelines settings menu provides parameters for retention policy and some other general settings. It does not give information about the service connections usage history.
Option B is incorrect because the Service hooks menu provides subscriptions for Azure DevOps event notifications. It does not give information about the service connections usage history.
Option D is incorrect because the Agent pools menu provides a pool of computing infrastructure with installed agent software to run the pipeline jobs. It does not give information about the service connections usage history.
For more information about service connections, please visit the below URLs: 

https://docs.microsoft.com/en-us/azure/devops/pipelines/library/service-endpoints?view=azure-devops&tabs=yaml
https://borzenin.com/service-endpoint-usage/