Which Is the Main Reason for Sanctions NOT Being Able

Multiple Choice

Which is the main reason for sanctions NOT being able to pressure North Korea into changing its behavior?

A) North Korea's trade and financial relations with the rest of the world are limited.
B) China has refrained from implementing substantial sanctions against its neighbor.
C) The tension that prevails between the United States and North Korea.
D) It sees nuclear weapons as the only way to survive its repressive regime.