A company hired an external consultant to assist with required system upgrades to a critical business application. A systems administrator needs to secure the consultant's access without sharing passwords to critical systems. Which of the following solutions should most likely be utilized?

PAM (Privileged Access Management) software is the most suitable solution because it specifically addresses the need to manage and secure privileged accounts, such as those used by external consultants accessing critical systems, without directly sharing credentials. PAM solutions typically involve vaulting credentials, session monitoring, and just-in-time access, enhancing security and accountability. TACACS+ is an authentication, authorization, and accounting (AAA) protocol, but it doesn't inherently manage privileged access or prevent password sharing in the way PAM does. SAML (Security Assertion Markup Language) is for federated identity management and single sign-on, not for securing privileged access to critical systems. An SSO platform simplifies user authentication but doesn't provide the granular control and security features for privileged accounts that PAM offers. Role-based access control (RBAC) defines permissions based on roles, which is a good practice, but it's a concept of access control, not a solution for managing and securing privileged credentials themselves.