Correct Option: D

The Khyber Pass is a 53-kilometer (33-miles) passage through the Hindu Kush mountain range. It connects the northern frontier of Pakistan with Afghanistan. At its narrowest point, the pass is only 3 meters wide. On the north side of the Khyber Pass rise the towering, snow-covered mountains of the Hindu Kush. The Khyber Pass is one of the most famous mountain passes in the World. It is one of the most important passes between Afghanistan and Pakistan. It is the best land route between India and Pakistan and has had a long and often violent history. Conquering armies have used the Khyber as an entry point for their invasions. It was also been a major trade route for centuries.