A team is currently using a Git-based repository in Azure repositories. The repository is being used for the source code of a web-based application. The repository has a main master branch and many feature topics branches. There is a large volume of feature requests. It is becoming difficult to follow the history of changes to the master branch. You have to design a pull request merge strategy that would meet the following requirements. Allows consolidation of all commit histories
Merge the changes into a single commit
You need to choose the right branching strategy. Which of the following would you choose?

Answer options:

A.Git fetch
B.fast-forward merge
C.slow-merge
D.squash merge

Answer – D 
You can implement this with the squash merge technique. 
This is also given in the Microsoft documentation. 

Since this is clearly given in the Microsoft documentation, all other options are incorrect. 
For more information on the squash merge technique, please visit the following URL- 

https://docs.microsoft.com/en-us/azure/devops/repos/git/merging-with-squash?view=azure-devops