Your company recently purchased an Office 365 subscription. Your company has an on-premises Active Directory Domain Services (AD DS) domain. You configure smartcard authentication support for some specific users.
You want to ensure that users can access all Office 365 applications without typing their password. You also want to ensure that they use the same password for the AD DS company domain and Office 365.
You need to deploy a solution that meets all the company's requirements.
Which solution should you deploy?
You should deploy AD FS. You need your users to be able to use all Office 365 applications without typing the password every time they need to use the application. This means that you need to implement a Single Sign-On (SSO) solution. You have also configured smartcard authentication support. This is the only solution that enables SSO and also allows smartcard authentication with Office 365 applications for your users.
You should not deploy Active Directory Federation Services (AD FS) and Seamless SSO. Seamless SSO is an Azure AD Connect feature that is not supported by AD FS.
You should not deploy Azure AD Connect with password hash synchronization or pass-through authentication and Seamless SSO. None of these options allows users with a smartcard to authenticate to Office 365 applications.
You should not deploy Azure AD Connect with password hash synchronization or pass-through authentication. These options do not provide SSO on their own. You would need to enable Seamless SSO on Azure AD Connect to support SSO. These options do not meet the requirement of authenticating users with smartcards either.