TASK DEFINITION: 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.
PROBLEM: A student conducts an investigation. In order to make a valid conclusion, she must  
 (A) have a testable hypothesis. (B) place the data in a graph. (C) use the best technology. (D) test multiple variables.

SOLUTION: A

PROBLEM: Which action does a kitten learn from its mother?  
 (A) how to grow (B) how to meow (C) how to hunt mice (D) how to nurse milk

SOLUTION: C

PROBLEM: Which change in the state of water particles causes the particles to become arranged in a fixed position?  
 (A) boiling (B) melting (C) freezing (D) evaporating

SOLUTION:
C