What does this traffic sign indicate?

This traffic sign indicates the presence of horse riders on the road, suggesting that drivers should be cautious.

1. **Danger in Connection with Horses**: This part is correct because it warns drivers to be alert to potential hazards related to horses crossing or riding near the roadway.

2. **Priority of Horse Riders**: This choice is also relevant; it indicates that if there are horse riders present, they may have priority over motor vehicles, particularly in areas where they might be crossing or moving alongside the road.

3. **No Through-Traffic due to Bridle Path**: This option is aimed at informing drivers about specific areas where motor vehicle access is restricted. If a bridle path is present, it may indicate a prohibition against vehicle traffic to ensure the safety and access of horse riders.

In summary, recognizing all elements of this sign helps ensure safety for both drivers and horse riders, aligning with German traffic regulations that prioritize the protection of vulnerable road users.