A Development Team Is Using AWS CodeCommit to Version Control

A development team is using AWS CodeCommit to version control application code and AWS CodePipeline to orchestrate software deployments. The team has decided to use a remote master branch as the trigger for the pipeline to integrate code changes. A developer has pushed code changes to the CodeCommit repository, but noticed that the pipeline had no reaction, even after 10 minutes. Which of the following actions should be taken to troubleshoot this issue?

A) Check that an Amazon CloudWatch Events rule has been created for the master branch to trigger the pipeline.
B) Check that the CodePipeline service role has permission to access the CodeCommit repository.
C) Check that the developer's IAM role has permission to push to the CodeCommit repository.
D) Check to see if the pipeline failed to start because of CodeCommit errors in Amazon CloudWatch Logs.