You want to utilize SSO across domains.

To overcome browsers that block third-party cookies and enableSingle Sign-On (SSO)across domains, the best practice is to use acentralized hosted loginpage. This approach avoids reliance on third-party cookies by centralizing the authentication process on a single domain.

Option A: Incorrect. Using a site group and enabling SSO may still rely on third-party cookies, which modern browsers increasingly block.

Option B: Incorrect. An SSO segment is a grouping mechanism for sites but does not address the issue of third-party cookie blocking.

Option C: Incorrect. Using a hosted page for the parent site does not fully resolve the cross-domain SSO challenge caused by third-party cookie restrictions.

Option D: Correct. Acentralized hosted loginpage ensures that authentication occurs on a single domain, avoiding the need for third-party cookies and enabling seamless SSO across domains.

References:

SAP Customer Data Cloud - Centralized Hosted Login

Cross-Domain SSO Best Practices