Final answer:
The 'reverse curve ahead' sign indicates that there are two turns in opposite directions separated by a short straight section, with the first turn to the right.
Step-by-step explanation:
The sign 'reverse curve ahead' is used to indicate a specific road layout that drivers should be prepared for. The correct option among the provided choices regarding what this sign indicates is: 1) Two turns in opposite directions separated by a tangent of less than 120 m, with the first turn to the right. Understanding road signs is crucial for safe driving practices. When you see a 'reverse curve ahead' sign, it alerts you to slow down and prepare for the upcoming changes in the direction of the road.