A company is using AWS CodeCommit as its source code repository. After an internal audit, the compliance team mandates that any code change that go into the master branch must be committed by senior developers.
Which solution will meet these requirements?

A. Create two repositories in CodeCommit: one for working and another for the master. Create separate IAM groups for senior developers and developers. Assign the resource-level permissions on the repositories tied to the IAM groups. After the code changes are reviewed, sync the approved files to the master code commit repository.
B. Create a repository in CodeCommit. Create separate IAM groups for senior developers and developers. Assign code commit permissions for both groups, with code merge permissions for the senior developers group. Create a trigger to notify senior developers with a URL link to approve or deny commit requests delivered through Amazon SNS. Once a senior developer approves the code, the code gets merged to the master branch.
C. Create a repository in CodeCommit with a working and master branch. Create separate IAM groups for senior developers and developers. Use an IAM policy to assign each IAM group their corresponding branches. Once the code is merged to the working branch, senior developers can pull the changes from the working branch to the master branch.
D. Create a repository in CodeCommit. Create separate IAM groups for senior developers and developers. Use AWS Lambda triggers on the master branch and get the user name of the developer at the event object of the Lambda function. Validate the user name with the IAM group to approve or deny the commit.