C. They made a treaty with China to explore the area
Answer:
On December 13, peace talks between the United States and North Vietnam collapsed. The North Vietnamese and American negotiators traded charges and countercharges as to who was to blame. Infuriated, President Nixon ordered plans drawn up for retaliatory bombings of North Vietnam. Linebacker II was the result. The impact of the so-called “Christmas Bombings” on the final agreement was difficult to assess. Some historians have argued that the bombings forced the North Vietnamese back to the negotiating table. Others have suggested that the attacks had little impact, beyond the additional death and destruction they caused.
Explanation:
Rules of law and participation
Look at the image, that should answer your question. Good luck!