You create a web application and use Azure AD B2C for user sign-up and profile management. 
Please select three authentication protocols that Azure AD B2C supports.

Answer options:

A.RADIUS
B.OpenID Connect
C.LDAP
D.SALM
E.Kerberos
F.OAuth

Correct Answers: B, D and F 
Microsoft Azure AD provides a variety of features, like Application management, Authentication, Business-to-Business (B2B), Business-to-Customer (B2C), Conditional access, Identity protection, Privileged identity management (PIM), etc. 
Azure AD Business-to-Business (B2B) functionality offers guest users and external partners` management. And Azure AD Business-to-Customer (B2C) helps you use external identity providers for your apps or API users to sign up, sign in, and manage their profiles. 
When you create an application and register it within Azure AD B2C, you can enable users to use their own external identity accounts to register for your app`s login. Azure AD B2C accommodates single sign-on (SSO) solutions for all your web, mobile, and API solutions. 
Azure AD B2C supports three industry-standard authentication protocols: OAuth (ver.1 and 2), OpenID Connect, and SALM. Users can use credentials of the third-party identity providers, like OAuth2 (Microsoft, Twitter, Facebook, Google, Apple, Amazon, WeChat, etc.), OpenID (Azure AD, Azure AD B2C), and SAML 2.0 (Salesforce).
Option A is incorrect because Azure AD B2C does not support RADIUS. RADIUS stands for Remote Authentication Dial-in User Service — a network protocol that provides authentication, accounting, authorization services.
Option C is incorrect because LDAP stands for Lightweight Directory Access Protocol — a network protocol for managing various devices. It is a foundation for the Microsoft Active Directory but not an authentication protocol for the Azure AD B2C.Option E is incorrect because Kerberos is a robust network protocol for client-server communication that uses a cryptographic key. But it does not provide identity management services, and Azure AD B2C does not support it.
For more information about Azure AD Business-to-Customer (B2C), please visit the below URLs: 

https://docs.microsoft.com/en-us/azure/active-directory-b2c/overview
https://docs.microsoft.com/en-us/azure/active-directory-b2c/add-identity-provider
https://docs.microsoft.com/en-us/azure/active-directory/fundamentals/active-directory-whatis