What defines the term 'inaccessible track'?

Answer: B — A method to restrict train entry on a non-controlled track

The term 'inaccessible track' refers to a method of restricting train entry on a non-controlled track. This definition is crucial as it highlights the safety protocols in place to ensure that trains do not enter areas where they should not be, such as those undergoing maintenance, repair, or otherwise unsafe for operation. Establishing restrictions helps protect workers on or near the track, maintain safety throughout the rail network, and prevent accidents that could occur from unauthorized train access. In this context, it effectively communicates the importance of control measures in managing rail traffic, especially on tracks that do not have active supervision.