With the spectroscopic method, why is finding Earth-sized planets harder than finding giant planets? Choose one: OA. It's a matter of atmospheres. Unlike giant planets, Earth-sized planets have atmospheres that refract light, making them extremely hard to detect. O B. It's a matter of size. A smaller planet's periodic presence is harder to disentangle from a star's stellar surface activity than a larger planet. O C. It's a matter of how planets orbit a star. Earth-sized planets tend to orbit in a random fashion that is outside of the plane of most of the other planets in the star system, whereas giant planets tend to orbit in the plane of most of the other planets. O D. It's a matter of planetary system formation. Earth-sized planets are hard to find because not many exist; they are rarely formed relative to giant planets.