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.

Example Input: Which difference between water and ice results in ice floating on cold water?
(A) heat (B) shape (C) density (D) volume
Example Output: C

Example Input: People are developing electric cars that would replace gasoline-burning cars. One major advantage of the electric car is that it
(A) accelerates faster. (B) causes less pollution. (C) gives a smoother ride. (D) needs no battery.
Example Output: B

Example Input: Which tools are best used to determine the speed of a turtle as it walks along a path?
(A) Meter stick and graduated cylinder (B) Stopwatch and meter stick (C) Balance and metric ruler (D) Balance and stopwatch
Example Output:
B