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 type of organism is at the lowest level of the food chain?  
 (A) autotroph (B) heterotroph (C) carnivore (D) omnivore

Answer: A


Question: The basic life functions of an organism are carried on by  
 (A) cells (B) nutrients (C) atoms (D) hormones

Answer: A


Question: When ocean waters become too warm, some whales travel to colder water. This movement is an example of  
 (A) nest building (B) hunting (C) migrating (D) hibernating

Answer:
C