State C is a WTO member state and a party to NAFTA

State C is a WTO member state and a party to NAFTA. It has made no specific agreement under either GATS or NAFTA as to its road transport sector. Now, tow freight companies, one from State D (a WTO member state) and one from State E (a party to both the WTO and NAFTA), wish to provide overland freight transportation services in State C using trucks operating out of terminals in State D and State E but using the roads in State C. May they do so? To what extent? Why?