Final answer:
At night, it is hardest to see pedestrians. Street lights, road signs, and other motorists usually provide some form of illumination, making them easier to see compared to pedestrians.
Step-by-step explanation:
At night, it is hardest to see D. pedestrians. When it is dark outside, pedestrians may be less visible due to the limited amount of light available. This is especially true in poorly lit areas or when pedestrians are dressed in dark clothing. Street lights, road signs, and other motorists usually provide some form of illumination, making them easier to see compared to pedestrians.