Explanation
It federates credentials control to authorized applications. This means that users can access multiple applications across different domains or organizations using one set of credentials, without having to share their passwords with each application1. The applications rely on a trusted identity provider (IdP) to authenticate the users and grant them access.
It establishes trust between Identity store and service provider. This means that the IdP and the service provider (SP) have a mutual agreement to exchange identity information using standard protocols, such as SAML, OpenID Connect, or OAuth2. The IdP and the SP also share metadata and certificates to ensure secure communication and verification.
It improves affiliated applications adoption rates. This means that users are more likely to use applications that are connected to their existing identity provider, as they do not have to create or remember multiple passwords3. This also reduces the friction and frustration of logging in to different applications, and enhances the user experience.
The other options are not features of federated single sign-on solutions because:
It solves all identity and access management problems. This is false, as federated single sign-on solutions only address the authentication aspect of identity and access management, not the authorization, provisioning, governance, or auditing aspects. Federated single sign-on solutions also have some challenges, such as complexity, interoperability, and security risks.
It enables quick and easy provisioning and deactivating of users. This is not necessarily true, as federated single sign-on solutions do not automatically create or delete user accounts in the service provider applications. Users still need to be provisioned and deprovisioned manually or through other mechanisms, such as just-in-time provisioning or SCIM.
References: Federated Identity Management vs. Single Sign-On: What's the Difference?, What is single sign-on?, Single Sign-On (SSO) Solution, [Identity Management vs. Access Management: What's the Difference?], [Federated Identity Management Challenges], [Just-in-Time Provisioning for SAML], [SCIM User Provisioning]