You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).
Q: Paragraph: At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react.
 Question: As we fill a balloon with air the number of reactions in the balloon 
 Choices: A)increase 
B)decrease
A:
increase