The correct answer is B.
At the end of the Korean war in 1953, an armistice agreeement (and not a peace agreeement!) was signed. It approved the end of hostilities until a peace treaty could be actually enacted.
The division was maintained after the war and the armistice and continues nowadays, with the existence of two separate countries: North Korea and South Korea. The border that separates them is located along the 38th paralell. Hence, the peace treaty has not been signed yet.