Read the passage from Anthem, by Ayn Rand. In this passage, the narrator is exploring an old, abandoned underground tunnel.

But we pulled at the grill (on the ground) and it gave way. And then we saw iron rings as steps leading down a shaft into a darkness without bottom.… It was a great tunnel. Its walls were hard and smooth to the touch; it felt like stone, but it was not stone. On the ground there were long thin tracks of iron, but it was not iron; it felt smooth and cold as glass. We knelt, and we crawled forward, our hand groping along the iron line to see where it would lead. But there was an unbroken night ahead.

What can you infer about the tracks described in the bold text?


They are lanes on a highway.


They are long tubes of glass.


They are subway or train tracks.