I believe the answer is D, Cells get energy by taking in nutrients from food. Correct me if I'm wrong.
They use radiometry and pyrometry
NASA uses the Transiting Exoplanet Survey Satelite (TESS) telescope that employes this technology
This telescope measures the brightness/luminosity of stars. When this brightness drops regularly, every more or less in the same number of years, then there is the likelihood of a planet orbiting the star. The dip in brightness of the star is directly proportional to the size of the planet and the distance between the star and the orbiting planet.
Answer: Option D. Vestigial trait
Explanation:
Vestigial traits simply involves those traits (such as organs, structurrs or behaviors) which are found or occurs in organisms or animals, that have lost all or most of their original function through evolution. These vestigial structures were organs that performed some important functions in the organism at one point in the past. In most cases, organs or traits once identified as vestigial simply had an unrecognized function.