Which of the following are protocols belonging to the OSI suite of protocols? (Choose two)
Which of the following are protocols belonging to the OSI suite of protocols? (Choose two)
The OSI (Open Systems Interconnection) model is a conceptual framework used to understand network interactions. X.500 is a series of standards for directory services, which are designed within the framework of the OSI model. IS-IS (Intermediate System to Intermediate System) is a protocol used for routing, and it is based on the OSI model's network layer protocols. Therefore, these two, X.500 and IS-IS, belong to the OSI suite of protocols.
C+D are correct. They were part of the original set of protocols. https://en.wikipedia.org/wiki/OSI_protocols