GKFix MCQ Question

Stars twinkle because

• A. the intensity of light emitted by them changes with time
• B. the distance of the stars from the earth changes with time
• C. the refractive index of the different layers of the earth's atmosphere changes continuously, consequently the position of the image of a star changes with time
• D. the light from the star is scattered by the dust particles and air molecules in the earth's atmosphere