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.

[EX Q]: Background Paragraph: Earthquakes may take place every day near a volcano. But before an eruption, the number and size of earthquakes increases. This is the result of magma pushing upward into the magma chamber. This motion causes stresses on neighboring rock to build up. Eventually the ground shakes. A continuous string of earthquakes may indicate that a volcano is about to erupt. Scientists use seismographs to record the length and strength of each earthquake. 
Story: Pam and Jane were two researchers. Pam studied sedimentary rocks while Jane studied volcanoes and related phenomena, such as earthquakes. 
Question: Which researcher didn't observe what happens before a volcanic eruption?
[EX A]: Pam.

[EX Q]: Background Paragraph: Reduction of the area of Arctic sea ice reduces the planet's average albedo, possibly resulting in global warming in a positive feedback mechanism. Research shows that the Arctic may become ice free in the summer for the first time in human history within by 2040. Estimates vary for when the last time the Arctic was ice free: 65 million years ago when fossils indicate that plants existed there to as few as 5,500 years ago; ice and ocean cores going back 8000 years to the last warm period or 125,000 during the last intraglacial period.Warming temperatures in the Arctic may cause large amounts of fresh meltwater to enter the north Atlantic, possibly disrupting global ocean current patterns. Potentially severe changes in the Earth's climate might then ensue.As the extent of sea ice diminishes and sea level rises, the effect of storms such as the Great Arctic Cyclone of 2012 on open water increases, as does possible salt-water damage to vegetation on shore at locations such as the Mackenzie's river delta as stronger storm surges become more likely.Global warming has increased encounters between polar bears and humans. Reduced sea ice due to melting is causing polar bears to search for new sources of food. Beginning in December 2018 and coming to an apex in February 2019, a mass invasion of polar bears into the archipelago of Novaya Zemlya caused local authorities to declare a state of emergency. Dozens of polar bears were seen entering homes and public buildings and inhabited areas. 
Story: Mike was reading about climate change. The author compared two different time periods, era A and era B. Era A was set in the present day. But era B was set in the year 2040. Mike was surprised to find how Arctic area would change in the coming years. 
Question: In which time more fresh meltwater would enter the north Atlantic, era A or era B?
[EX A]: era B.

[EX Q]: Background Paragraph: Arbuscular mycorrhizal fungi vary across many environmental gradients. Their tolerance to freezing and drying is known to shift between AM fungal taxa. AM fungi become less prevalent and diverse at higher soil nutrient and moisture concentrations, presumably because both plants allocate less carbon to AM fungi and AM fungi reallocate their resources to intraradical hyphae in these environmental conditions. Over the long term, these environmental conditions can even create local adaptation between plant hosts, AM fungi and the local soil nutrient concentrations. 
Story: Carrie bought two parcels of farmland. The Northern one had soil with lots of arbuscular mycorrhizal fungi, while the Southern parcel  had almost no traces of AM fungi. 
Question: Which parcel had AM fungi reallocate more resources to intraradical hyphae?
[EX A]:
Southern.