I believe your answer is D
Within the visible range of light, red<span> light waves are scattered the least by atmospheric gas molecules. So at sunrise and </span>sunset, when the sunlight travels a long path through the atmosphere to reach our eyes, the blue light has been mostly removed, leaving mostly red<span> and yellow light remaining.</span>
Antoine Henri Becquerel discovered radioactivity when he was studying
X- rays.
He had been studying phosphorescent uranium ores and hypothesized that they might absorb sunlight and reemit it as X-rays.
His hypothesis was wrong, but his experiments led to the discovery of <em>natural radioactivity</em>.