The correct options are
C Khyber Pass
D Bolan Pass
Most of the mountains in the world act as a formidable barrier. Due to this, mountain passes have played a key role in trade, war, and human migration. Two such passes which are important in the history of India are the Khyber and Bolan passes in the Hindukush mountains. These mountain passes were connected to the famous Silk Route that were essential to China's engagement with Central Asia and Arabia.