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 scientific guess about the cause and effect of an event is called  
 (A) a variable. (B) a theory. (C) a hypothesis. (D) an observation.
answer:
C


question:
Use of nuclear fuel would most likely reduce human contributions to which environmental problem?  
 (A) ozone thinning (B) landfill creation (C) shoreline erosion (D) greenhouse heating
answer:
D


question:
The production of sweat is typically a response to an increase in the body's  
 (A) blood circulation. (B) temperature. (C) respiration. (D) heart rate.
answer:

B