A company stores configuration files in an Amazon S3 bucket. These configuration files must be accessed by applications that are running on Amazon EC2 instances.
According to AWS security best practices, how should the company grant permissions to allow the applications for access the S3 bucket?

A. Use the AWS account root user access keys.
B. Use the AWS access key ID and the EC2 secret access key.
C. Use an IAM role with the necessary permissions.
D. Activate multi-factor authentication (MFA) and versioning on the S3 bucket.