The correct answers are A and D. Amazon EC2 Instance Connect is a feature that allows system administrators to securely connect to their EC2 instances using the AWS Management Console or AWS CLI without the need to manage SSH keys manually. It provides a more secure way to access instances. AWS Systems Manager Session Manager is another method that enables starting interactive sessions with instances directly from the AWS Management Console or through the AWS CLI, offering secure and auditable access without the need to open inbound SSH ports. Option B is incorrect because Amazon Linux 2 AMI is a Linux distribution and does not support RDP, which is a protocol used for Windows systems. Option C is incorrect because AWS Batch is a service for running batch computing workloads and does not provide a method for connecting to EC2 instances. Option E is incorrect because Amazon Connect is a cloud-based contact center service and is not related to connecting to EC2 instances.