Which of the Following Is Not a Way for a Country

Which of the following is not a way for a country to use IFRS?

A) Require foreign companies listed on that country's stock exchange to use IFRS for consolidated financial statements.
B) Allow foreign companies listed on that country's stock exchange to use IFRS.
C) Allow that country's companies listed on its stock exchange to use IFRS.
D) Adopt IFRS as that country's national GAAP.
E) All of these are ways a country can use IFRS.