How should an identity architect automate provisioning and deprovisioning of users into Salesforce from an external system?

Universal containers(UC) has a custom, internal-only, mobile billing application for users who are commonly out of the office. The app is configured as a connected App in salesforce. Due to the nature of this app, UC would like to take the appropriate measures to properly secure access to the app. Which two are recommendations to make the UC? Choose 2 answers

An architect needs to set up a Facebook Authentication provider as login option for a salesforce customer Community. What portion of the authentication provider setup associates a Facebook user with a salesforce user?

Sales users at Universal containers use salesforce for Opportunity management. Marketing uses a third-party application called Nest for Lead nurturing that is accessed using username/password. The VP of sales wants to open up access to nest for all sales uses to provide them access to lead history and would like SSO for better adoption. Salesforce is already setup for SSO and uses Delegated Authentication. Nest can accept username/Password or SAML-based Authentication. IT teams have received multiple password-related issues for nest and have decided to set up SSO access for Nest for Marketing users as well. The CIO does not want to invest in a new IDP solution and is considering using Salesforce for this purpose. Which are appropriate license type choices for sales and marketing users, giving salesforce is using Delegated Authentication?
Choose 2 answers

An architect has successfully configured SAML-BASED SSO for universal containers. SSO has been working for 3 months when Universal containers manually adds a batchof new users to salesforce. The new users receive an error from salesforce when trying to use SSO. Existing users are still able to successfully use SSO to access salesforce. What is the probable cause of this behaviour?