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:
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.
answer:
D


question:
The nucleus of the cell controls cell activity. Which body system performs a similar function in humans?  
 (A) circulatory system (B) central nervous system (C) skeletal system (D) integumentary system
answer:
B


question:
Bernice studied some organisms that live together in a field. In which way is a rabbit similar to the plant it eats?  
 (A) They both need energy to survive. (B) They both consume other organisms. (C) They both absorb water from the ground. (D) They both produce their own food from sunlight.
answer:

A