Explanation

According to the AWS Shared Responsibility Model:

AWS Responsibility (Security OF the Cloud):

• A. Securing the virtualization layer - AWS is responsible for the security of the cloud infrastructure, including the hypervisor and underlying hardware
• D. Patching the operating system on Amazon RDS instances - For managed services like Amazon RDS, AWS handles the operating system patching and maintenance

Customer Responsibility (Security IN the Cloud):

• B. Patching the operating system on Amazon EC2 instances - Customers are responsible for patching the guest operating system on EC2 instances
• C. Enforcing a strict password policy for IAM users - Customers manage IAM policies and user access controls
• E. Configuring security groups and network ACLs - Customers configure network security controls

The key distinction is that AWS manages the underlying infrastructure and managed services, while customers are responsible for security configurations and management within their cloud environment.