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]: The Sun is classified as  
 (A) an organism (B) a decomposer (C) a star (D) a planet
[EX A]: C

[EX Q]: The yellow-throated longclaw is a bird that lives on the dry savanna of Africa. It looks almost exactly like another bird, the western meadowlark of North America. Although the birds look very similar, they are not even in the same taxonomic family. Scientists think the birds look alike because the two species developed under similar environmental pressures, even though they developed thousands of miles apart. Which process does their development demonstrate?  
 (A) sexual selection (B) disruptive selection (C) divergent evolution (D) convergent evolution
[EX A]: D

[EX Q]: Which force produces energy as heat?  
 (A) pull (B) gravity (C) friction (D) magnetic
[EX A]:
C