Which two recommendations should the Salesforce IAM architect make to the IT Lead?

A real estate company wants to provide its customers a digital space to design their interior decoration options. To simplify the registration to gain access to the community site (built in Experience Cloud), the CTO has requested that the IT/Development team provide the option for customers to use their existing social-media credentials to register and access.

The IT lead has approached the Salesforce Identity and Access Management (IAM) architect for technical direction on implementing the social sign-on (for Facebook, Twitter, and a new provider that supports standard OpenID Connect (OIDC)).

Which two recommendations should the Salesforce IAM architect make to the IT Lead? Choose 2 answers
A . Use declarative registration handler process builder/flow to create, update users and contacts.
B. Authentication provider configuration is required each social sign-on providers; and enable Authentication providers in community.
C. For supporting OIDC it is necessary to enable Security Assertion Markup Language (SAML) with Just-in-Time provisioning (JIT) and OAuth 2.0.
D. Apex coding skills are needed for registration handler to create and update users.

Answer: B,D