Correct option is C
Durand line separates Pakistan and Afghanistan.
The Durand Line is a 2,430-kilometer border that separates Pakistan and Afghanistan. It was established in 1893 by Sir Mortimer Durand, a British diplomat, when he negotiated a treaty with the Afghan Amir Abdur Rahman Khan. The line is named after Sir Durand, who was the Foreign Secretary of British India at the time.