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: A girl found the skull of an animal. She did not know what the animal was but she was sure that it preyed on other animals for its food. What clue led to this conclusion?  
 (A) The eye sockets faced sideways. (B) The skull was much longer than it was wide. (C) There was a projecting ridge along the top of the skull. (D) Four of the teeth were long and pointed. (E) The jaws could move sideways as well as up and down.

Answer: D


Question: Claudia's teacher places a photograph of an organism on the board. He asks Claudia to determine if the organism is a plant or an animal. The answer to which question will best help Claudia determine if the organism is a plant or an animal?  
 (A) Does the organism have cells? (B) Does the organism reproduce? (C) Does the organism live in the forest? (D) Does the organism make its own food?

Answer: D


Question: What are the basic structural units of living organisms?  
 (A) cells (B) nuclei (C) organs (D) tissues

Answer:
A