Which country faced significant challenges for conquerors due to its rugged landscape?

The correct answer is Afghanistan, as the country is well-known for its rugged and mountainous terrain, which has historically posed significant challenges for military conquests and invasions. The Hindu Kush mountain range, which runs through the central part of Afghanistan, creates a formidable natural barrier that complicates the movement of troops and resources. This difficult geography has not only hindered conquerors but also contributed to Afghanistan's rich history of resistance against foreign invasions, such as during the British Wars in the 19th century and more recently during conflicts involving various global powers.

Other countries listed have diverse landscapes, but they do not present the same level of challenge posed by Afghanistan's topography. Turkey, while having mountains, also features plains and a more navigable landscape. Pakistan has mountainous regions but also extensive lowland areas that are less challenging for movement. Iran, too, has a variety of terrains but has seen successful campaigns in its flatter regions. Thus, the unique combination of steep mountains and challenging valleys in Afghanistan has made it particularly difficult for conquerors throughout history.