A Security Architect Has Been Assigned to a New Digital

A security architect has been assigned to a new digital transformation program. The objectives are to provide better capabilities to customers and reduce costs. The program has highlighted the following requirements: Long-lived sessions are required, as users do not log in very often. The solution has multiple SPs, which include mobile and web applications. A centralized IdP is utilized for all customer digital channels. The applications provide different functionality types such as forums and customer portals. The user experience needs to be the same across both mobile and web-based applications. Which of the following would BEST improve security while meeting these requirements?

A) Social login to IdP, securely store the session cookies, and implement one-time passwords sent to the mobile device
B) Certificate-based authentication to IdP, securely store access tokens, and implement secure push notifications.
C) Username and password authentication to IdP, securely store refresh tokens, and implement context-aware authentication.
D) Username and password authentication to SP, securely store Java web tokens, and implement SMS OTPs.