The correct answers are A and D because network infrastructure and virtualization of infrastructure and physical security of hardware are AWS responsibilities according to the AWS shared responsibility model. The AWS shared responsibility model is a framework that defines the division of responsibilities between AWS and the customer for security and compliance. AWS is responsible for the security of the cloud, which includes the global infrastructure, such as the regions, availability zones, and edge locations; the hardware, software, networking, and facilities that run the AWS services; and the virtualization layer that separates the customer instances and storage. The customer is responsible for the security in the cloud, which includes the customer data, the guest operating systems, the applications, the identity and access management, the firewall configuration, and the encryption. The other options are incorrect because they are not AWS responsibilities according to the AWS shared responsibility model. Security of application data, guest operatingsystems, and credentials and policies are customer responsibilities according to the AWS shared responsibility model. Reference: [AWS Shared Responsibility Model]