In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Q: Washington (CNN) With tensions rising between the US and North Korea, the Pentagon on Sunday called for the isolated communist nation to avoid destabilizing the situation further. "We call on (North Korea) to refrain from provocative, destabilizing actions and rhetoric, and to make the strategic choice to fulfill its international obligations and commitments and return to serious talks," Pentagon spokesman Gary Ross said. "North Korea's unlawful weapons programs represent a clear, grave threat to US national security." The statement came just hours after a North Korean newspaper said Pyongyang was ready to take out a US aircraft carrier conducting drills with Japanese destroyers near the Philippines.The US responded to a threat in North Korean mediaOne US aircraft carrier is drilling with the JapaneseTrump speaks to leaders of China and Japan 
 Question:North Korea conducted its fifth nuclear weapons test last September and displayed a series of missiles at a military parade on an important _ holiday earlier this month before firing one off, which the US said went down in flames shortly after the launch.
A: 
North Korea