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: For a given medium, sound has a slower speed at lower temperatures.
 Question: If Jim turns the thermostat down in his room while listening to music, what will happen to the speed of the sound waves in the room? 
 Choices: A)they will speed up 
B)they will slow down
they will slow down

Paragraph: At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react.
 Question: Mike is watching how particles of reactants function, and sees that they are very far apart. Considering that the concentration of them is very low, the chance of them colliding together is 
 Choices: A)high 
B)low
low

Paragraph: This means that as wavelengths get shorter, more waves move past a particular spot in the same amount of time.
 Question: Wavelengths that are longer will be 
 Choices: A)faster 
B)slower

slower