The correct answer is: D. Ionosphere.
The ionosphere is a region of Earth’s atmosphere that is ionized by solar radiation. It extends from about 60 to 1,000 kilometers (37 to 620 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 extends from about 50 to 85 kilometers (31 to 53 miles) above Earth’s surface. The mesosphere is the coldest layer of Earth’s atmosphere, with temperatures as low as -90 degrees Celsius (-130 degrees Fahrenheit).
The stratosphere is the layer of Earth’s atmosphere that extends from about 12 to 50 kilometers (7.5 to 31 miles) above Earth’s surface. The stratosphere is the layer of Earth’s atmosphere that contains the ozone layer.
The troposphere is the layer of Earth’s atmosphere that extends from Earth’s surface to about 12 kilometers (7.5 miles) above Earth’s surface. The troposphere is the layer of Earth’s atmosphere that contains most of Earth’s weather.