What causes the change of seasons on earth?

Earth’s revolution and inclination of its axis

The correct answer is Option (3) - Earth’s revolution and inclination of its axis

The Earth's axis is not oriented vertically, but is tilted by 23.5 degrees. The north end of the axis is always pointed toward the North Star as the Earth revolves around the sun. This tilt, combined with its revolution around the Sun, causes seasonal changes. (When it’s summer in the northern hemisphere, it’s winter in the southern, and vice versa.) If the axis was not tilted, our year-round climate would be rather boring and many places on Earth wouldn’t receive much light!