What is the primary cause for the change in seasons?

A.

the tilt of Earth's axis

B.

the distance of Earth from the Sun

C.

the position of the Moon between Earth and the Sun

D.

the speed at which Earth rotates

A. The tilt of Earth's axis

Explanation:

The Earth's rotational axis is tilted about 23.5° relative to its orbital plane as it revolves around the Sun.

Thus, the angle of the sun in the sky varies over the year.

For example, if you lived at 45°N, the angle of the Sun in the sky would be 45°, and it would be the beginning of spring (see the diagram below).

The maximum angle of the Sun would be 68.5°. The Sun would be high overhead, and it would be the beginning of summer.

The minimum angle of the Sun would be 21.5°. The Sun would be low in the sky, and it would be the beginning of winter.

B. is wrong. The Earth is closer to the Sun during winter in the northern hemisphere.

C. is wrong. The position of the Moon affects sunlight on Earth only during a solar eclipse.

D is wrong. The speed at which the Earth rotates affects only the length of the day.