You run a 2000-engineer organization. You are about to begin using AWS on a large scale for the first time. You want to integrate with your existing identity management system running on Microsoft Active Directory because your organization is a power-user of Active Directory. How should you manage your AWS identities in the most simple manner?

Answer options:

A.Use AWS Directory Service Simple AD.B.Use AWS Directory Service AD Connector.
C.Use an Sync Domain running on AWS Directory Service.
D.Use an AWS Directory Sync Domain running on AWS Lambda.

Answer – B
AD Connector is a directory gateway with which you can redirect directory requests to your on-premises Microsoft Active Directory without caching any information in the cloud. 
Once set up, AD Connector offers the following benefits:
Your end-users and IT administrators can use their existing corporate credentials to log on to AWS applications such as Amazon WorkSpaces, Amazon WorkDocs, or Amazon WorkMail.
You can manage AWS resources like Amazon EC2 instances or Amazon S3 buckets through IAM role-based access to the AWS Management Console.
You can consistently enforce existing security policies (such as password expiration, password history, and account lockouts) whether users or IT administrators access resources in your on-premises infrastructure or the AWS Cloud.
You can use AD Connector to enable multi-factor authentication by integrating with your existing RADIUS-based MFA infrastructure to provide an additional layer of security when users access AWS applications.
For more information on the AD Connector, please visit the below URL:
http://docs.aws.amazon.com/directoryservice/latest/admin-guide/directory_ad_connector.html