What is the meaning of the following traffic sign?

- No entry for vehicle carriers.
- No entry for vehicles, including trolleys.
- Correct answer: No entry for horse drawn vehicles and non-harnessed animals.
- Entry is permitted for horsemen only.
Why this is the answer
The correct answer in the official bank: No entry for horse drawn vehicles and non-harnessed animals.
A round sign with a red border is a prohibition sign, so it forbids entry and does not permit it. The horse figure stands for animals, and the prohibition applies both to horse drawn vehicles (vehicles harnessed to animals) and to non-harnessed animals. So it must not be read as permission for horsemen only.