An application running on Amazon EC2 instances needs to access an Amazon DynamoDB table. Both resources are in the same AWS account. <br/><br/>What is the MOST secure way to grant the EC2 instances access to the DynamoDB table?

Create an IAM user with DynamoDB permissions. Store the access keys in a configuration file on the EC2 instances.

Create an IAM role with permissions to access the DynamoDB table. Attach the role to an EC2 instance profile and assign it to the instances.

Modify the DynamoDB resource-based policy to allow access from the EC2 instances' private IP addresses.

Store IAM user credentials in AWS Secrets Manager and configure the application to retrieve them at runtime.