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: When your brain senses that your body temperature is increasing, it sends messages to the blood vessels in the skin to increase in diameter.
 Question: The blood vessels near the top of the skin do what when it's cool? 
 Choices: A)enlarge 
B)contract
A:
contract