You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.
--------
Question: The radiant energy that comes to Earth from the Sun is  
 (A) only one wavelength that we see as yellow. (B) a narrow band of wavelengths that is entirely visible light. (C) mostly long wavelengths that become heat energy. (D) a range of many wavelengths from long to very short.

Answer: D


Question: The planets in the solar system revolve around the Sun because the Sun is  
 (A) made of hydrogen and helium. (B) older than other objects in the solar system. (C) the source of most heat and light energy. (D) the strongest source of gravity in the solar system.

Answer: D


Question: For many years, scientists have found fossils in rock layers in all parts of the world. Eventually scientists discovered that many of the rock layers showed the same pattern of older fossils being located in deeper rock layers and younger fossils being located in shallower layers. This discovery is an example of how scientific knowledge changes as  
 (A) fossils are preserved in different ways. (B) conclusions about fossils are revised into questions. (C) fossils are formed in different areas. (D) new fossil evidence is reviewed.

Answer:
D