Your team has defined a new project in Azure DevOps. This is for a web application. You need to ensure that whenever code is checked in, a build is run automatically. 
You decide to enable the Pull request trigger setting from the Triggers tab of the build pipeline. 
Would this fulfill the requirement?

Answer options:

A.Yes
B.No

Answer – A 
You can set up pull request triggers for both Azure Repos or GitHub repositories. From within your project, Select Pipelines > Releases, and then select your release pipeline. Under the Pull request trigger section, select the toggle button to enable it. 
Pull requests provide an effective way to review code changes before it is merged into the codebase. However, these changes can introduce issues that can be tricky to find without building and deploying your application to a specific environment. Pull request triggers enable you to set up a set of criteria that must be met before deploying your code. You can use pull request triggers with code hosted on Azure Repos or GitHub. 
Setting up pull request deployments is a two step process: Set up a pull request trigger.
Set up branch policies (in Azure Repos) or status checks (in GitHub) for your release pipeline.
With pull request triggers, anytime you raise a new pull request for the designated branch, a release is triggered automatically to start the deployment to the designated environments. The deployment status will then be displayed on the pull request page. Pull request triggers can help you maintain better code quality, release with higher confidence, and discover any issues early on in the development cycle. 
This is more pertinent to a pull request. The Microsoft documentation mentions the following on this setting. 

For more information on using triggers in the build pipeline, please visit the below URL- 

https://docs.microsoft.com/en-us/azure/devops/pipelines/build/triggers?view=azure-devops&tabs=classic
https://docs.microsoft.com/en-us/azure/devops/pipelines/release/deploy-pull-request-builds?view=azure-devops