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:
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.
answer:
A


question:
Which of the following is the most likely cause of earthquakes?  
 (A) shifting rock layers (B) crashing meteorites (C) rotation of the core (D) magnetic force
answer:
A


question:
In Costa Rica a small tree, the acacia, provides shelter and food for ants. The ants protect the acacia by removing other insects and vines that might harm it. Which term best describes the relationship between the acacia and the ants?  
 (A) competition (B) mutualism (C) parasitism (D) predation
answer:

B