What Is Most-Favored-Nation Trading Status

What is most-favored-nation trading status?

A) When countries give each other the same trade concessions they give to all other countries.
B) When a country gives special trade privileges to a close ally.
C) When a country spares no expense to increase trade with another country.
D) When a country has the wealthiest and most developed economy.
E) When a country promotes trade with military allies.