What does this traffic sign indicate?

You chose answers 1 and 2, and that’s correct. This warning sign (red triangle) with a snowflake means there is a risk of winter road conditions ahead, especially icy patches and snow-covered or packed-snow sections.

The key idea is: it’s not telling you “it is icy right now everywhere,” but warning you that conditions can change quickly and grip can suddenly be much worse than expected, for example on bridges, in shaded areas, in valleys, or after snowfall.

What you should do when you see it: reduce speed early, increase following distance, avoid harsh braking/steering, and be prepared for longer stopping distances. If conditions require it, use winter tires and, where needed, snow chains.

It does not mean “avalanches.” Avalanche danger is indicated by a different warning sign showing falling rocks/snow coming down a slope, not a snowflake.