An application makes calls to AWS services using the AWS SDK. The application runs on Amazon EC2 instances with an associated IAM role. When the application att...

An application makes calls to AWS services using the AWS SDK. The application runs on Amazon EC2 instances with an associated IAM role. When the application attempts to access an object within an Amazon S3 bucket; the Administrator receives the following error message: HTTP 403: Access Denied.
Which combination of steps should the Administrator take to troubleshoot this issue? (Choose three.)