Task: Question Answering
Input (English): Background Paragraph: Blood vessels help regulate body processes by either constricting (becoming narrower) or dilating (becoming wider). These actions occur in response to signals from the autonomic nervous system or the endocrine system. Constriction occurs when the muscular walls of blood vessels contract. This reduces the amount of blood that can flow through the vessels (see Figure below ). Dilation occurs when the walls relax. This increases blood flows through the vessels. 
Story: Greg is a physician working for the city hospital. Today he is seeing two patients, patient A and patient B. He noticed that patient A's blood vessels are constricted, but blood vessels of patient B are dilated. He needs to prescribe medicine according to his observation. 
Question: Which patient would have less blood passing through the vessels, patient A or patient B?
Output (English): patient A.