Correct option is D
The correct answer is:(d), Population is scattered and its difficult to develop other means of transport.
Air transport is crucial in regions like Canada, Alaska, large parts of Russia, and Australia due to their low population density and challenging landscapes, including vast forests, ice caps, and remote areas. Given the impracticality of developing extensive road or rail networks in such terrain, air transport serves as an efficient means of connecting scattered populations and remote locations, providing vital accessibility and connectivity where other transportation modes may be less viable.