The best explanation for the differences in the distribution of solar energy on Earth's surface is A. Earth's curved shape and tilt on its axis do not allow the sun's rays to fall evenly on its surface.
This option accurately describes how the curvature of the Earth leads to varying angles at which sunlight strikes different parts of the planet. The tilt of the Earth’s axis also contributes to seasonal variations in solar energy distribution. The combination of these factors results in uneven heating of the Earth’s surface, influencing temperature and climate patterns.