instruction:
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.
question:
Lichens are symbiotic organisms made of green algae and fungi. What do the green algae supply to the fungi in this symbiotic relationship?  
 (A) carbon dioxide (B) food (C) protection (D) water
answer:
B


question:
Which of these substances is correctly identified as a mineral?  
 (A) coal (B) quartz (C) granite (D) sandstone
answer:
B


question:
Which is the best tool for measuring the temperature of lake water?  
 (A) Meter stick (B) Balance (C) Graduated cylinder (D) Thermometer
answer:

D