The signs in the photograph indicate...

A)roadworks 300 metres ahead.
B)bends and an intersection on the right.
C)bends and a narrowing due to roadworks.Correct
The sign on the left indicates danger due to the proximity of a section of road where the carriageway narrows on the left side. Having a yellow background also indicates that the narrowing is located in a roadworks section.
The sign on the right indicates danger due to the proximity of a series of closely spaced bends, the first one to the left. The supplementary panel at the bottom indicates the length of this dangerous section.