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 Q]: Which of these elements is found in the greatest amount in organisms?  
 (A) carbon (B) iron (C) lead (D) neon
[EX A]: A

[EX Q]: Diamonds are sometimes used as the tips of drill bits. Which physical property of a diamond MOST likely makes it a good cutting tool?  
 (A) its electrical properties (B) its thermal properties (C) its hardness (D) its density
[EX A]: C

[EX Q]: Herbivores that evolved on grassy plains are likely to naturally select for traits different than herbivores that evolved in rain forests. Which trait is a plains herbivore most likely to develop over thousands of years?  
 (A) long legs for running (B) sharp claws for climbing (C) webbed feet for swimming (D) prehensile tail for hanging from trees
[EX A]:
A