Question: China has the longest border with which of the following country
Correct Answer: C. Mongolia
Explanation: China’s longest border, stretching about 4,6774,6774,677 km (2,9062,9062,906 mi), is with Mongolia, which in turn has its longest border with China, followed by Russia (~3,6453,6453,645 km) and India (~3,4883,4883,488 km).