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.
--------
Question: Background Paragraph: Gibberellins are hormones that cause the plant to grow. When gibberellins are applied to plants by scientists, the stems grow longer. Some gardeners or horticulture scientists add gibberellins to increase the growth of plants. Dwarf plants (small plants), on the other hand, have low levels of gibberellins ( Figure below ). Another function of gibberellins is to stop dormancy (resting time) of seeds and buds. Gibberellins signal that it’s time for a seed to germinate (sprout) or for a bud to open. 
Story: Keith has four plants in his backyard, plant A, plant B, plant C, and plant D. Plant A is very large, but plant B is smaller. Plant C and D are the same size. He applied some gibberellins to plant C, but didn't apply anything to plant D. He got curious about why some plants are bigger, while others are not. 
Question: Which plant would see increase in growth, plant C or plant D?

Answer: plant C.


Question: Background Paragraph: Protozoa generally feed by engulfing and digesting other organisms. As consumers, they have various roles in food chains and webs. Some are predators. They prey upon other single-celled organisms, such as bacteria. In fact, protozoa predators keep many bacterial populations in check. Other protozoa are herbivores. They graze on algae. Still others are decomposers. They consume dead organic matter. There are also parasitic protozoa that live in or on living hosts. For example, the protozoan that causes malaria lives inside a human host. For their part, protozoa are important food sources for many larger organisms, including insects and worms. 
Story: An astronaut has just landed on a new martian planet and encounters two different protozoa. The first protozoa he finds, protozoa X, is eating algae that is floating on top of water. The second protozoa, protozoa Y, is found eating bacteria. Upon further study, it is found that these are the only foods these two specific protozoa eat. 
Question: Which protozoa is a herbivore?

Answer: protozoa X.


Question: Background Paragraph: Plants called epiphytes grow on other plants. They obtain moisture from the air and make food by photosynthesis. Most epiphytes are ferns or orchids that live in tropical or temperate rainforests (see Figure below ). Host trees provide support, allowing epiphyte plants to obtain air and sunlight high above the forest floor. Being elevated above the ground lets epiphytes get out of the shadows on the forest floor so they can get enough sunlight for photosynthesis. Being elevated may also reduce the risk of being eaten by herbivores and increase the chance of pollination by wind. 
Story: Hawk and Brunt were two colleagues studying about plants. Later on, Hawk got specialized in normal plants, while Brunt decided to learn more about epiphytes. 
Question: Which colleague studied more about plants that obtain moisture from the air?

Answer:
Brunt.