A. 438 km
B. 527 km
C. 523 km
D. 823 km
The total length of Pak-China is 438 kilometres (272 mi). It traverses the highest mountain range of the Karakorum in Pakistan. The world’s tallest mountain Goodwin Austin (K2) lies on the border between Pak-China. This line was drawn in the English men period in the subcontinent. During the British Raj in the Britisher sent his envoy, Sir Claude MacDonald, to China and asked them to draw this borderline but Chinese never give a positive response to their proposal and that’s the reason the border never formalized then. For more study about Pak-China Border, you can visit this link here.
Note: In many papers the option of 438 km often not found. In that situation, you can choose the option with 523 km.
Read more about Pak-Afghan Borderline here.