A sign with a yellow background and a black triangle showing a truck going down signifies what?

Answer: B — Hill sign

A sign with a yellow background and a black triangle showing a truck going down indicates a hill or downgrade ahead. This type of sign is specifically designed to warn drivers about the presence of a steep hill that may require them to adjust their speed and be cautious while driving. When approaching a downhill slope, it’s crucial for drivers to be attentive to the potential for loss of control, especially if they are driving a heavy vehicle, such as a truck. This signage serves as a proactive alert, allowing drivers to prepare for the descent and take necessary safety measures, such as slowing down and using lower gears. The other options, while they may be important traffic signs, do not accurately describe the specific meaning of a yellow background with a black triangle featuring a truck going downhill. This particular sign focuses on the shape and color scheme associated with warnings of changes in terrain that can affect vehicle handling.