You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.
Q: Background Paragraph: Many people enjoy riding in hot air balloons. Some use them for romantic picnics and marriage proposals. Others race in competitions. Being above the earth gives a whole new perspective on the world around us. As the beginning of a hot air balloon ride, the balloon is flat because the pressure inside the balloon equals the pressure outside. When the air inside the balloon is heated, the speed of movement of those air molecules increases and the pressure goes up. After a while the balloon is completely expanded and the flight is ready to take off.
Story: Bob just came from a hot air balloon ride. On his way home he saw two balloons, balloon A and balloon B. Balloon A was flat, but balloon B was inflated. He was wondering how balloons go up so effortlessly.
Question: Which balloon would have faster inside air movement, balloon A or balloon B?
A:
balloon B.