The correct answer is: D. there would be no change of seasons.
The Earth’s axis is tilted at an angle of 23.5 degrees relative to its orbital plane. This tilt is what causes the seasons. During the summer, the Northern Hemisphere is tilted towards the sun, so the days are longer and the sun is higher in the sky. During the winter, the Northern Hemisphere is tilted away from the sun, so the days are shorter and the sun is lower in the sky. If the Earth’s axis were not tilted, there would be no change in the amount of sunlight that each hemisphere receives, and there would be no seasons.
Option A is incorrect because the Earth’s year is determined by the time it takes the Earth to orbit the sun, not by the tilt of the Earth’s axis.
Option B is incorrect because the length of winter is determined by the tilt of the Earth’s axis, not by the length of the Earth’s year.
Option C is incorrect because the temperature of summer is determined by the amount of sunlight that the Earth’s surface receives, not by the tilt of the Earth’s axis.