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:
Rock layers with sand-sized particles were most likely deposited by  
 (A) wind. (B) water. (C) glaciers. (D) landslides.
answer:
A


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:
How has the invention of the personal computer helped people the most?  
 (A) by replacing paper (B) by reducing pollution (C) by improving transportation (D) by increasing communication
answer:

D