Why do we have seasons on earth? a) as earth goes around the sun and earth's axis remains pointed toward polaris, the northern and southern hemispheres alternately receive more and less direct sunlight. b) the tilt of earth's axis constantly changes between 0 and 23 1/20, giving us summer when earth is tilted more and winter when it is straight up. c) earth's orbital distance from the sun varies, so that it is summer when we are closer to the sun and winter when we are farther from the sun. d) the hemisphere that is tilted toward the sun is closer to the sun than the hemisphere that is tilted away.

The correct option is: A) As Earth goes around the Sun and Earth's axis remains pointed toward Polaris, the Northern and Southern hemispheres alternately receive more and less direct sunlight.

Explanation:

Seasons on Earth are the changes in the weather caused due to the titled axis of the Earth, relative to the orbital or ecliptic plane, while orbiting around the Sun. The Earth's axis of rotation is tilted approximately by an angle of 23.4°.

This results in the change in the intensity of the sunlight received by the Earth's surface, due to which the southern and the northern hemispheres experience opposite seasons.