Firstly, all the known definitions of organic compounds excludes Carbonic acid and it's salt from organic compounds except if 'C' is present in the cation.
Secondly, Sodium is a metal which organic compounds cannot posses as a compound.
Lastly, there is absence of C-H bond which is present in all the organic compounds.
Hence, we can conclude that is an inorganic compound though there is presence of Carbon atom in it.