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: Turner et al (2006) derived crash prediction models for this report’s predecessor and found a
pronounced ‘safety in numbers’ effect in the models. Using the crash prediction model for mid-block
locations, generic motorist and cyclist volumes can be used to demonstrate the impacts on the
expected crash rate of varying motor vehicle and cycle volumes. As shown in figure 2.20, an increase
in the proportion of cyclists to the overall traffic volume causes an increase in expected crashes at
mid-block locations, but the crash rate increases at a decreasing rate. That is to say, the crash rate per
cyclist goes down as the cycle volume increases. 
Story: There were a lot of motorcycles on Interstate 17 last week. On Monday, there were 1355 motorcyclists. On Tuesday, there were 2355 motorcyclists. On Wednesday, there were 3351 motorcyclists. On Thursday, there were 4351 motorcyclists. On Friday, there were 5351 motorcyclists. On Saturday, there were 6351 motorcyclists. On Sunday, there were 7351 motorcyclists. 
Question: What day had a lower crash rate per cyclist: Monday or Sunday?

A: Sunday.
****
Q: Background Paragraph: In the natural world, ants of some species (initially) wander randomly, and upon finding food return to their colony while laying down pheromone trails. If other ants find such a path, they are likely not to keep travelling at random, but instead to follow the trail, returning and reinforcing it if they eventually find food (see Ant communication).

Over time, however, the pheromone trail starts to evaporate, thus reducing its attractive strength. The more time it takes for an ant to travel down the path and back again, the more time the pheromones have to evaporate. A short path, by comparison, gets marched over more frequently, and thus the pheromone density becomes higher on shorter paths than longer ones. Pheromone evaporation also has the advantage of avoiding the convergence to a locally optimal solution. If there were no evaporation at all, the paths chosen by the first ants would tend to be excessively attractive to the following ones. In that case, the exploration of the solution space would be constrained. The influence of pheromone evaporation in real ant systems is unclear, but it is very important in artificial systems.[8]. 
Story: Ricky, an entomologist, is observing an ant colony in his back yard. After some observation, he discovers that all the ants travel down one of two distinct paths in order to find food to bring back to the colony. After taking some measurements, Ricky sees that path A is approximately 100 meters in length, and path B is approximately 150 meters in length. Ricky is now trying to make some scientific conclusions based on these observations. 
Question: Which path will be marched over less frequently?

A: path B.
****
Q: Background Paragraph: Communication is any way that animals share information. Many animals live in social groups. For these animals, being able to communicate is essential. Communicating increases the ability of group members to cooperate and avoid conflict. Communication may help animals work together to find food and defend themselves from predators. It also helps them find mates and care for their offspring. In addition, communication helps adult animals teach the next generation learned behaviors. Therefore, communication generally improves the chances of animals surviving and reproducing. 
Story: Manny and Dean were two classmates. They had to prepare for a school project so they decided to learn about animals. Manny studied animal communication, while Dean studied animal feeding patterns and nutrition. 
Question: Which student learned about the ability of animal group members to cooperate?

A:
Manny.
****