You are given a science question (easy-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: Which statement describes animal embryos?  
 (A) display all the features of an adult (B) represent the earliest stage of development (C) have the same number of cells as a fertilized egg (D) have half the number of chromosomes as an adult

Answer: B


Question: Some scientists have suggested that the Moon was formed when a large body struck Earth and broke off a piece of Earth billions of years ago. Which observation would best support this suggestion?  
 (A) The rocks of the Moon are older than Earth rocks. (B) The Earth has free standing water, but the Moon does not. (C) The Earth and the Moon are gravitationally locked together. (D) The chemical composition of Moon rocks is similar to Earth rocks.

Answer: D


Question: Which discovery revealed that the universe contains many structures composed of millions of stars?  
 (A) novas (B) galaxies (C) black holes (D) solar systems

Answer:
B