Concept:Rail transport is most suitable for carrying large quantities of heavy and bulky goods.
Explanation:Railways have a very high load-carrying capacity.
This makes them economical for moving heavy and bulky cargo over long distances.
Option A is incorrect because railway tracks and trains require high maintenance costs.
Option B is incorrect because rail services can be delayed due to weather, signal failures, or congestion.
Option D is incorrect because rail transport cannot provide door-to-door delivery on its own.
It needs trucks or other vehicles for the first and last mile.
Therefore, the clear advantage of rail transport is that it carries bulky and heavy goods.
Answer:C. bulky and heavy goods