Explanation:

Atlas Mountains: Atlas Mountains are a series of mountain ranges in northwestern Africa, running generally southwest to northeast that form the geologic backbone of the countries of the Maghrib (the western region of the Arab world) - Morocco, Algeria, and Tunisia. Their thick rim rises to form a high sill separating the Mediterranean basin to the north from the Sahara to the south, thus constituting a barrier. Hence pair 1 is not correctly matched.
• Zagros Mountains: Zagros Mountains is a mountain range in southwestern Iran, extending northwest-southeast from the border areas of eastern Turkey and northern Iraq to the Strait of Hormuz. Situated mostly in what is now Iran, it forms the extreme western boundary of the Iranian plateau, though its foothills to the north and west extend into adjacent countries. Hence pair 2 is correctly matched.
Altai Mountains: This is a complex mountain system of Central Asia extending approximately in a southeast-northwest direction from the Gobi desert to the West Siberian Plain, through China, Mongolia, Russia, and Kazakhstan. At present the mountains are opened to extensive resource extration operations. Hence pair 3 is not correctly matched.
• Drakensberg Mountains: The Drakensberg mountains form the eastern portion of the Great Escarpment, which encloses the central Southern African plateau. These mountains are located within the borders of South Africa and Lesotho. The range is the main watershed of South Africa and is the source of the Orange River. Hence pair 4 is correctly matched
Hence option c is the correct answer.