The correct answer is B. Xen.
An AMI (Amazon Machine Image) is a virtual machine image that contains a set of operating system files and other software configured to run on Amazon Web Services (AWS). AMIs are used to create Amazon Elastic Compute Cloud (EC2) instances, which are virtual servers that run on AWS.
Xen is a virtualization hypervisor that allows multiple operating systems to run on a single physical server. Xen is used by AWS to provide EC2 instances.
Yen is the currency of Japan.
Ben is a common English name.
Multi-Factor Authentication (MFA) is a security process that requires users to provide two or more forms of identification in order to access a system. MFA is used to prevent unauthorized access to systems by requiring users to provide something they know (such as a password) and something they have (such as a security token).