The correct answer is D. Layer 7 protocols.
Layer 7 is the application layer, which is the highest layer in the Open Systems Interconnection (OSI) model. It is responsible for providing services to the user, such as passwords, resource sharing, file transfer, and network management.
Layer 4 is the transport layer, which is responsible for providing reliable data transfer between two hosts.
Layer 5 is the session layer, which is responsible for managing the communication between two hosts.
Layer 6 is the presentation layer, which is responsible for formatting data for presentation to the user.
E. None of the above is incorrect because all of the options are layers in the OSI model.