Which configuration is described as 'Narrow gauge single track'?

• A. Narrow gauge single track
• B. Narrow gauge multiple track
• C. Standard gauge single track
• D. Mine dump

Answer: (A)

This is testing how rail configurations are described by two features: gauge and number of tracks. Gauge is the distance between the two rails; narrow gauge means that distance is smaller than standard gauge. Single track means there is only one line for trains to use, so trains traveling in opposite directions share that same track and must be coordinated at passing points.

So, the description "Narrow gauge single track" refers to a rail system where the rails are closer together than standard gauge and there is just one track for trains. The other possibilities would either use a wider (standard) gauge, or use more than one track, or describe something not related to a rail layout (mine dump).