The answer is Earth’s tilt. (C) The earth is tilted on its axis just a little bit which causes one part to be closer to the sun than the others at a specific time
That's logical, but not the case, for Earth. Instead, Earth has seasons because our planet's axis of rotation is tilted at an angle of 23.5 degrees relative to our orbital plane – the plane of Earth's orbit around the sun. The tilt in the axis of the Earth is called its obliquity by scientists.
