instruction:
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 of these animals has a young form that looks the most like the adult form?  
 (A) moth (B) human (C) frog (D) butterfly
answer:
B


question:
To calculate the relative age of rocks, geologists use the rate of radioactive decay of isotopes present in their samples. What is the term used for the original amount of the elemental isotopes being investigated?   
 (A) rare earth isotopes (B) son isotopes (C) daughter isotopes (D) parent isotopes
answer:
D


question:
Which of the following organisms have the greatest effect on an ecosystem because of the changes they make to their environment?  
 (A) bees building a hive in a hollow tree (B) wasps building a nest in a leafy bush (C) beavers building a dam across a stream (D) fish digging a burrow on a river bottom
answer:

C