instruction:
You are given a science question (hard-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:
Joanne's science teacher cautioned the class to be skeptical when learning about new scientific discoveries. Why is it important to be skeptical about new discoveries in science?  
 (A) because many scientific discoveries are not based on facts (B) because most scientific discoveries have no scientific value (C) because most scientists make errors when formulating scientific discoveries (D) because all scientific discoveries must be examined critically before they can be accepted
answer:
D


question:
What occurs if the body's renal system fails to work?  
 (A) Gas exchange is impaired. (B) Blood oxygenation no longer occurs. (C) Metabolic waste builds up in the blood. (D) Nutrients are no longer transported to organs.
answer:
C


question:
During which stage of its life cycle does a butterfly spend the most time eating plant leaves?  
 (A) adult (B) egg (C) larva (D) pupa
answer:

C