What Is Not an Example of Non-Tariff Barriers

What is not an example of non-tariff barriers?

A) France requires the use of the French language in any offer, presentation or advertisement, whether written or spoken.
B) Product testing and certification requirements have made the entry of many foreign companies into Japanese markets quite difficult.
C) Since the EU chose ISO 9000 as a basis to harmonise varying technical norms of its member states, some of its trading partners have accused it of erecting a new trade barrier against outsiders.
D) All of the alternatives are incorrect.