Xiao Min saw a row of wall clocks on the wall at the reception desk of a hotel in Guangzhou (pictured). The reason she explained to her grandmother is correct () A. The time difference is

The earth is an opaque sphere, and the sun can only illuminate half of it at any time. Because the earth keeps spinning, the illuminated part (the daytime hemisphere) is constantly transformed into the dark part (the nighttime hemisphere), which is the alternation of day and night. Because the earth rotates, the eastern part of the same latitude can see the sunrise a moment earlier, so there is a difference between morning and evening at different longitudes.

So choose: a.