A circular yellow sign marked with a black X and the letters “RR” warns of:

Correct answer: C – A railroad crossing ahead
The circular railroad warning sign alerts drivers that they are approaching a railroad crossing. It appears in advance of the tracks, while a crossbuck identifies the crossing itself. Drivers should watch for trains, signals, gates, and traffic conditions as they approach.
Source: Arizona Driver License Manual and Customer Service Guide — Section 3, “Railroad Warning Sign”.


