The earth is tilted at an angle of 23.5o with respect to the plane of its orbit around the sun. If the amount of tilt were increased to 40o, we would expect in middle latitudes:

The correct answer is: A. Hotter summers and colder winters than at present.

The Earth’s tilt is the angle between the Earth’s axis of rotation and its orbital plane. The Earth’s tilt is currently 23.5 degrees, but it has varied over time. If the Earth’s tilt were increased to 40 degrees, the Northern and Southern Hemispheres would receive more direct sunlight during their respective summers. This would cause the summers to be hotter and the winters to be colder.

Option B is incorrect because the Earth’s tilt does not affect the amount of sunlight that the Earth receives during the winter. The Earth receives the same amount of sunlight during the winter as it does during the summer. However, the Earth’s tilt does affect the angle at which the sunlight hits the Earth’s surface. During the winter, the sunlight hits the Earth’s surface at a more oblique angle, which means that it is spread out over a larger area. This results in less sunlight per unit area, which makes the winters colder.

Option C is incorrect because the Earth’s tilt does not affect the amount of sunlight that the Earth receives during the summer. The Earth receives the same amount of sunlight during the summer as it does during the winter. However, the Earth’s tilt does affect the angle at which the sunlight hits the Earth’s surface. During the summer, the sunlight hits the Earth’s surface at a more direct angle, which means that it is concentrated in a smaller area. This results in more sunlight per unit area, which makes the summers hotter.

Option D is incorrect because the Earth’s tilt does not affect the amount of sunlight that the Earth receives during the winter. The Earth receives the same amount of sunlight during the winter as it does during the summer. However, the Earth’s tilt does affect the angle at which the sunlight hits the Earth’s surface. During the winter, the sunlight hits the Earth’s surface at a more oblique angle, which means that it is spread out over a larger area. This results in less sunlight per unit area, which makes the winters colder.

Option E is incorrect because the Earth’s tilt does affect the amount of sunlight that the Earth receives at different latitudes. The Earth’s tilt causes the Northern and Southern Hemispheres to receive more direct sunlight during their respective summers. This would cause the summers to be hotter and the winters to be colder.