I think your answer should be either the third choice or second choice. They both make sense to me but the other two are definitely not it. Hope this helps! =^-^=
Answer:
North and South Korea remain in a state of heightened military readiness
Because both countries want to invaded each other.
Explanation:
As a result of the WWII the Korean peninsula was divided along the parallel 38 this division created a communist North Korea and a capitalist South Korea.
The tension created by this division is the result of a long conflict that actually started when Korea was Invaded by Japan from 1910 until 1945. After this the Soviet Union took control of the North while the United States of America took control of the south. the country.
North Korea and South Korea have their armies ready to engage in case of a military action of either country.