Concept:Railway transport operates on fixed tracks and timetables, whereas road transport can adapt to varied routes and destinations.
Explanation:Road vehicles provide door-to-door service and can easily change direction or stop anywhere along the journey.
Railways, however, are confined to their own tracks and cannot reach areas without rail lines.
They also follow rigid schedules, which reduces their ability to respond to immediate demands.
This makes railways less flexible than road transport in serving passengers and goods directly.
Therefore, the major drawback of railway transport when compared with road transport is its limited flexibility.
Answer:D. lack of flexibility