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: Many things can contribute to the development of a theory. A student made a list of some things that might help scientists develop a theory. Observations Calculations Conversations Publications From the student's list, which must be used in the development of every theory?
(A) Observations (B) Conversations (C) Publications and calculations (D) Calculations and conversations

SOLUTION: A

PROBLEM: The greatest amount of diversity can be found among which type of organism?
(A) plants (B) animals (C) bacteria (D) fungi

SOLUTION: C

PROBLEM: Farm fertilizers are often carried by runoff into the Mississippi River and down to the Gulf of Mexico, resulting in algae blooms. Which of these results from the decomposition of the algae blooms?
(A) an abundance of dissolved oxygen (B) dead zones where there are no fish (C) a reduction in atmospheric carbon dioxide (D) food webs with rapidly growing populations

SOLUTION:
B