What does the auto yellow luminous signal, visible from all directions, that the agricultural tractor carries on its upper part warn about?
A)That it cannot drive at a speed higher than 30 km/h.
B)That it is driving on urgent service.
C)Of its presence on the road or in its vicinity.Correct
# Explanation
The yellow luminous signal visible from all directions on the upper part of the agricultural tractor is a warning device. This flashing light warns other road users about the **presence of the agricultural vehicle**, which generally drives at low speed and may represent an obstacle. It does not indicate a specific speed limit or urgent service, but simply the presence of the tractor on the road or its vicinity.