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.

Ex Input:
The visible colors listed from shortest to longest wavelength are violet, blue, green, yellow, orange, and red. Which of the following accurately compares the frequency of these colors using this information?  
 (A) Blue has a higher frequency than violet. (B) Blue has a higher frequency than green. (C) Orange has a lower frequency than red. (D) Violet has a lower frequency than yellow.

Ex Output:
B


Ex Input:
A student plans to design a new toothpaste tube that will give the same amount of toothpaste every time it is squeezed. Which should the student do first when designing the new tube?  
 (A) make a data table of amounts of toothpaste (B) gather building materials (C) create models of old toothpaste tubes (D) draw a few possible solutions

Ex Output:
D


Ex Input:
A scientist makes a discovery while performing an investigation, but fails to maintain clear records of the tests performed. In which way does a lack of record keeping affect a scientist's work?  
 (A) It invalidates the procedures and conclusions. (B) It makes the data obtained in the study incorrect. (C) It prevents other scientists from validating the results. (D) It prohibits other scientists from developing new hypotheses.

Ex Output:

C