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.

Ex Input:
All of the following are functions of a cell membrane except  
 (A) surrounding and protecting the contents of the cell. (B) releasing waste products from the cell. (C) producing energy for cell processes. (D) allowing gases to enter the cell.

Ex Output:
C


Ex Input:
Research in which of these areas has the greatest impact on the environment?  
 (A) irradiating food (B) organic fertilizers (C) bacteria to clean up oil spills (D) developing larger, sweeter strawberries

Ex Output:
C


Ex Input:
Over time, dried lava from an old volcano is worn down and broken into small pieces. When these pieces pile up and are cemented together to form new rock, how would this new rock be classified?  
 (A) magma (B) igneous (C) sedimentary (D) metamorphic

Ex Output:

C