Which of the following can be applied to ensure that the application does not get promoted to the next stage in the pipeline if it has active bugs assigned to it?

Answer options:

A.Creating a trigger
B.Creating a deployment gate
C.Creating a pre-deployment approval
D.Creating a post-deployment approval

Answer – B 
The requirement is
 can be applied to ensure that the application does not get promoted to the next stage in the pipeline if it has active bugs assigned 
Option A: Trigger
The triggers directive defines the automated ways in which the Pipeline should be re-triggered. 
pipeline trigger help us when a large products have several components that are dependent on each other. These components are often independently built. When an upstream component (a library, for example) changes, the downstream dependencies have to be rebuilt and revalidated. 

https://docs.microsoft.com/en-us/azure/devops/pipelines/release/approvals/gates?view=azure-devops
https://docs.microsoft.com/en-us/azure/devops/pipelines/release/approvals/?view=azure-devops
https://docs.microsoft.com/en-us/azure/devops/pipelines/release/approvals/?view=azure-devops