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:
Which of the following Earth layers has the greatest density?  
 (A) crust (B) mantle (C) inner core (D) outer core
answer:
C


question:
A duck and turtle are different types of animals. In which way are the duck and the turtle alike?  
 (A) They both hibernate. (B) They both have feathers. (C) They both reproduce by laying eggs. (D) They both provide milk for their young.
answer:
C


question:
Which statement best describes how the Internet has helped improve life for many people?  
 (A) The Internet has eliminated the need for the library. (B) People are able to access information from many locations. (C) People can now do their work from home. (D) The Internet allows students to concentrate more on homework.
answer:

B