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: Diseases that can be transmitted between organisms are  
 (A) infectious. (B) inherited. (C) environmental. (D) congenital.

SOLUTION: A

PROBLEM: Air is composed of many different substances. Which of the following components of air is a compound rather than an element?  
 (A) Argon, Ar (B) Oxygen, O2 (C) Water, H2O (D) Nitrogen, N2

SOLUTION: C

PROBLEM: All living things are made up of prokaryotic or eukaryotic cells. Which function is found in both prokaryotic and eukaryotic cells?  
 (A) aerobic respiration (B) sexual reproduction (C) protein production (D) nitrogen fixation

SOLUTION:
C