A team is using Azure Resource Manager templates in their DevOps pipeline. The template needs to access secrets stored in the Azure Key Vault service. You, as a DevOps engineer, have to ensure that the resource manager template can successfully access the secrets using the principle of least privilege. 
Which of the following would you use TO SUCCESSFULLY ACCESS the data inside the Key Vault data plane?"

Answer options:

A.Key vault access policy
B.Key Vault advanced policy access
C.Role based access control
D.Azure policies

Answer – A 
In the Azure Key Vault you need to ensure that you click on “Enable access to Azure Resource Manager for template deployment,” as shown below. This allows the use of accessing resources in Azure Key Vault via resource manager templates. 

Since this is clearly given in the Microsoft documentation, all other options are incorrect. 
For more information on integrating Azure Key vault with ARM templates, please visit the below URL- 

https://docs.microsoft.com/en-us/azure/key-vault/general/overview-security#identity-and-access-management