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.

Which is an example of a chemical reaction?  
 (A) Vinegar added to baking soda forms a gas. (B) Water evaporates into air. (C) Sugar dissolves in water. (D) Corn kernels are crushed to form flour.
A

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.
B

Traveling in opposite directions, buses A and B are passing each other at the relative speed of 25 km/h, while a passenger on bus A walks toward the back of the bus at the speed of 5 km/h. What is the velocity of the passenger on bus A relative to bus B?  
 (A) 20 km/h in the direction of bus A (B) 20 km/h in the direction of bus B (C) 30 km/h in the direction of bus A (D) 30 km/h in the direction of bus B

A