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: 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: The example of someone having a positive experience with a drug is easy to see how drug dependence and the law of effect works. The tolerance for a drug goes up as one continues to use it after having a positive experience with a certain amount the first time.[38] It will take more and more to get that same feeling. This is when the controlled substance in an experiment would have to be modified and the experiment would really begin. The law of work for psychologist B. F. Skinner almost half a century later on the principles of operant conditioning, "a learning process by which the effect, or consequence, of a response influences the future rate of production of that response.[39]. 
Story: The Salvia Squad met to discuss their experiences. They all said they always had a great experience using salvia and used the same amount each time. They told how many times they used salvia. Weston used it once. Jerrod used it a few times. Lucio used it a lot. 
Question: Who has a lower tolerance for salvia: Weston or Lucio?
[EX A]: Weston.

[EX Q]: Background Paragraph: Alberta's electrical demand varies throughout the day and across the seasons. When individuals are fixing supper and using home appliances, demand for power goes up, as it does during heat waves and cold snaps. It tapers off during spring and fall. Like other mechanical devices, generators fail from time to time. If they are wind-powered, their output varies with the wind. 
Story: Alberta has had strange weather the last week. On Saturday, there was a cold snap. On Sunday, a heat wave happened. On Monday, it was normal. On Tuesday, another cold snap happened. On Wednesday, a heat wave happened. On Thursday, it was normal. On Friday, a heat wave happened in the morning and a cold snap happened at night. 
Question: What day did demand for power go up: Thursday or Wednesday?
[EX A]:
Wednesday.