You will be given a definition of a task first, then some input of the task.
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).

Paragraph: At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react.
 Question: If Mona has filled a balloon with helium and she removes some gas from it, what happens to the likelihood that the helium particles will collide with each other? 
 Choices: A)more likely 
B)less likely
Output:
less likely