Given the task definition and input, reply with output. 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: 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: Asa is running in a race and his body temperature increases. His skin's blood vessels _____ in diameter. 
 Choices: A)increase 
B)decrease
increase