Answer:
C) 30 by 10
Step-by-step explanation:
If the rail is ten meters long, and the rope is 10 meters long, they can travel 10 meters left of the rail, ten meters along the rail, ten meters right of the rail, and ten meters above the rail.
The answer is 12!
Hope this helps! :D
------The answers got taken down :(------
It is probably A. A is the most reasonable answer.