NFS - Network File System OSI layer

I have seen the NFS listed as both at the application layer and a session layer. Would i simply consider this at application layer?

Its application in my book.

Haha, good enough for me.

According to the oracle of all that is TCP/IP (i am of course referring to "The TCP/IP Guide", its says that NFS is all three layers of the OSI model (Session through to Application) but if you are looking at the TCP/IP Model, then its just Application because within the TCP/IP Model it wraps the top three layers into a single Application Layer.

It also goes a step further into defining the different functions of NFS that fits in each of the 3 OSI layers;

Application Layer - NFS Procedures and Operations which are tasks that are carried out on the files over the network.
Presentation Layer - XDR (External DAta Representation) allows data types to be defined in a consistant manor.
Session Layer - RPC (Remote Procedure Call) used to implement client/server internetworking functionality.

Would a question be asked on the CCNA regarding which layer of the OSI model does NFS function? If so, I would still use application because I should use the highest layer at which a protocol functions?

Hmm, i think if that question came up then i would have to say the same but you are able to comment and just quote the TCP/IP Guides response, lol