TASK DEFINITION: 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.
PROBLEM: Farmers plant fruit trees in an area that was once a grassy meadow. Which will most likely happen to the rabbits living in the meadow?  
 (A) They will learn to eat fruit. (B) They will learn to climb trees. (C) The number of their young will increase. (D) The size of their population will decrease.

SOLUTION: D

PROBLEM: Which of the following animals is an invertebrate?  
 (A) Squirrel (B) Sea gull (C) Cricket (D) Lizard

SOLUTION: C

PROBLEM: Which invention would a culture living above the Arctic Circle most likely develop?  
 (A) ice production (B) air conditioning (C) insulated clothing (D) irrigation canals

SOLUTION:
C