What does this panel indicate?

What does this panel indicate?
A)The distance from the location of the sign to where the hazard begins.
B)The length over which poorly surfaced pavement exists.
C)The length over which the indicated hazard lasts.Correct
The panel in the question indicates the length of the dangerous stretch.

On the other hand, when the panel does not display the two lateral arrows, it indicates the distance to the beginning of the hazard.
The hazard warning sign indicates a succession of dangerous curves close together, the first of them to the right (the rest are unknown). Therefore, we are going to have a 4 km stretch of dangerous curves.