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: In a classroom demonstration, a teacher pours sulfuric acid on some granulated sugar in a beaker. The sugar turns yellow and then black. Smoke rises and a strong smell is released. This demonstration is an example of what kind of change?  
 (A) chemical (B) physical (C) magnetic (D) electric

Answer: A


Question: A scientific guess about the cause and effect of an event is called  
 (A) a variable. (B) a theory. (C) a hypothesis. (D) an observation.

Answer: C


Question: Which best explains how the Appalachian Mountains formed?  
 (A) an ancient river flooded (B) an earthquake folded land (C) tectonic plates pulled apart (D) tectonic plates collided

Answer:
D