Answer:
B. Green
Explanation:
The change in wavelength that is caused when one object is moving towards another object from the perspective of the viewer is called the Doppler effect.
When objects move close to one another then wavelength reduces which is called blue shift while the opposite case causes the wavelength to increase which is called red shift.
Here, the color of the traffic light is yellow and you are getting closer to it so the wavelength should blue shift and green should appear.
