40. Which of the following measure is NOT employed to exert pressure on Russia?
(A) The United Nation issued an announcement to criticize Russia’s military action toward Ukraine.
(B) A referendum is held to declare that Ukrainians do not want to join the Russia Federation.
(C) Some of the economic activities between Russia and the U.S. are restricted, or even banned.
(D) Certain European countries, working together with the U.S., have imposed sanctions against Russia.