The picture is basically not necessary here, what the question is asking is : why do we have different time and different time zones?
Our time is divided into 24 hours, so you could ask: what happens every 24 hours? the answer is: the Earth rotates around its axis. So, the Earth motion responsible for this is its rotation around its axis.
Answer and Explanation:
Student B is correct, because Mercury is, in fact, possible to be visualized during the morning or evening twilight, that is, just after sunset, or just after sunrise, as times are necessary for the planet earth it has the right lighting to visualize it.
Student C is the one that is most incorrect, because at midnight the planet earth has very low luminosity so that Mercury can be visualized. Since it needs a low illumination, however existent for the planet Mercury to be seen.
