TASK DEFINITION: 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.
PROBLEM: Some birds fly south in the fall and return in the spring. This is an example of  
 (A) migration (B) camouflage (C) hibernation (D) growth

SOLUTION: A

PROBLEM: When a tree suffers from a decreased ability to transport materials within the phloem, what is directly impacted?  
 (A) volume of water in the xylem (B) flow of necessary nutrients (C) response to environmental factors (D) rate of photosynthesis in leaves

SOLUTION: B

PROBLEM: Which of these correctly identifies the way materials are transported in a plant?  
 (A) Xylem carries water from the roots to the leaves. (B) Phloem carries minerals from the roots to the leaves. (C) Xylem carries sugars from the flowers to the stems. (D) Phloem carries water from the flowers to the stems.

SOLUTION:
A