Which of the following statements are correct regarding the Ionosphere?
- It extends from about 80 km to 640 km above the Earth's surface.
- The D layer reflects high-frequency radio waves and appears during the day.
- The E layer, also known as the Kennelly-Heaviside layer, absorbs low-frequency radio waves.
- The F layer consists of F1 and F2 sub-layers reflecting medium and high-frequency radio waves.
1
1, 2, and 3
2
1, 3, and 4
3
1 and 4
4
All of the above