The wrong template selection is the most likely cause of the issue of newly provisioned Linux VMs running an earlier version of OS than they should be in a private IaaS environment. A template is a preconfigured image or blueprint of a VM that contains an OS, applications, settings, etc., that can be used to create new VMs quickly and consistently. A template may have different versions or updates depending on when it was created or modified. If a template is selected incorrectly or not updated properly, it may result in creating VMs with an older or different version of OS than expected.

API provider rate limiting is a restriction on the number of requests that can be made to a web service or application programming interface (API) within a certain time period. API provider rate limiting can cause a failure to access a public cloud API deployment, as it can reject or block any requests that exceed the limit. API provider rate limiting can be used by cloud providers to control the usage and traffic of their customers and prevent overloading or abuse of their resources. API provider rate limiting is the most likely cause for the developer being unable to access a public cloud API deployment that was working ten minutes prior. Reference: CompTIA Cloud+ Certification Exam Objectives, page 13, section 2.5

Single sign-on (SSO) is a type of authentication mechanism that allows users to access multiple systems or applications with a single login credential. SSO can help users have a seamless experience regardless of the collaboration solution being used, as it can eliminate the need for multiple logins and passwords for different systems or applications. SSO can also improve user convenience, productivity, and security, as it can simplify the login process, reduce login errors, and enhance password management. Reference: CompTIA Cloud+ Certification Exam Objectives, page 14, section 2.7