The ionosphere includes

mesosphere
thermosphere
thermosphere and exosphere
thermosphere, exosphere and mesosphere

The correct answer is: C. thermosphere and exosphere.

The ionosphere is a region of Earth’s upper atmosphere that is ionized by solar radiation. It is located above the mesosphere and extends from about 80 to 600 kilometers (50 to 370 miles) above Earth’s surface. The ionosphere is important for radio communications because it reflects radio waves back to Earth.

The mesosphere is the layer of Earth’s atmosphere that is located between the stratosphere and the thermosphere. It extends from about 50 to 80 kilometers (31 to 50 miles) above Earth’s surface. The mesosphere is the coldest layer of Earth’s atmosphere, with temperatures reaching as low as -100 degrees Celsius (-148 degrees Fahrenheit).

The thermosphere is the layer of Earth’s atmosphere that is located above the mesosphere. It extends from about 80 to 600 kilometers (50 to 370 miles) above Earth’s surface. The thermosphere is the hottest layer of Earth’s atmosphere, with temperatures reaching as high as 2,000 degrees Celsius (3,632 degrees Fahrenheit).

The exosphere is the outermost layer of Earth’s atmosphere. It extends from about 600 kilometers (370 miles) to 10,000 kilometers (6,200 miles) above Earth’s surface. The exosphere is very thin, with only a few atoms per cubic centimeter.