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: In the human body, which system functions primarily to defend the body against disease?  
 (A) digestive (B) immune (C) nervous (D) respiratory

SOLUTION: B

PROBLEM: What is the function of skin on the human body?  
 (A) Skin has pores that help the body sense odor. (B) Skin protects the body from harmful substances. (C) Skin brings oxygen directly into the body's bloodstream.

SOLUTION: B

PROBLEM: A student collects data about the dates and strengths of historical earthquakes in Nevada. Which of the following would be best for reporting the strengths of these earthquakes over time?  
 (A) a topographic map (B) a line graph (C) a series of photographs (D) a table of pictographs

SOLUTION:
B