Consider the following statements regarding homosphere and select the correct answer using codes given below: 1. It extends from the earth's surface up to an altitude of 80-90 km. 2. It has heterogeneous chemical composition. 3. Kennedy- Heaviside layer is an important part of ionosphere. 4. This part of the atmosphere is a function of revolutionary process in the atmosphere.

• A. Only 1 is correct
• B. Only 1 and 2 are correct
• C. Only 1, 2 and 3 are correct
• D. 1, 2, 3 and 4 are correct.