In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.

Example Input: Passage: Virginia has the highest concentration of technology workers of any state, and the fourth-highest number of technology workers after California, Texas, and New York. Computer chips became the state's highest-grossing export in 2006, surpassing its traditional top exports of coal and tobacco combined, reaching a total export value of $717 million in 2015. Northern Virginia, once considered the state's dairy capital, now hosts software, communication technology, defense contracting companies, particularly in the Dulles Technology Corridor.
The state has the highest average and peak Internet speeds in the United States, with the third-highest worldwide. Northern Virginia's data centers can carry up to 70% of the nation's Internet traffic, and in 2015 the region was the largest and fastest growing data center market in the nation.Forbes magazine has named Virginia the best state in the nation for business five times, and included it in their top five in 2018, as did CNBC in their America's Top States For Business 2018 rankings, with its deductions being mainly for the high cost of living. Additionally, in 2014 a survey of 12,000 small business owners found Virginia to be one of the most friendly states for small businesses. Virginia has 23 Fortune 500 companies, ranking the state sixth nationwide. Tysons Corner is one of the largest business districts in the nation.
Tourism in Virginia supported an estimated 210,000 jobs and generated $21.2 billion in 2012. Arlington County is the top tourist destination in the state by domestic spending, followed by Fairfax County, Loudoun County, and Virginia Beach. 
Question: What are the top four states with the highest concentration of technology workers?
Example Output: Virginia.

Example Input: Passage: After the Southwest became part of the U.S., explorers continued to look for good east–west routes along the 35th parallel. In 1853, a crew led by U.S. Army Lieutenant Amiel Whipple surveyed along a sandy wash in the northern part of the Petrified Forest. So impressed was Whipple by the petrified wood along the banks of the arroyo that he named it Lithodendron Creek (Stone Tree Creek). Geologist Jules Marcou, a member of the Whipple expedition, observed that the petrified trees were from the Triassic.A slightly later route along the parallel was a wagon road, built between 1857 and 1860, that involved experimental use of camels as transport. In the late 19th century, settlers and private stagecoach companies followed similar east–west routes. Homesteaders who stayed in the area developed cattle ranches on the grasslands, and cattle grazed in the Petrified Forest until the mid-20th century.Also close to the 35th parallel was the Atlantic and Pacific Railroad. Its opening in the early 1880s led to the founding of towns like Holbrook and Adamana. Visitors could stop at the Adamana train station, book a hotel room, and take a tour of what was then called the Chalcedony Forest. Over the years, the line changed hands, becoming the Atchison, Topeka and Santa Fe Railway, and then the BNSF. More than 60 BNSF trains, mostly carrying freight, pass through the park every day. U.S. Route 66, a former transcontinental auto highway developed in 1926 from part of the National Old Trails Road, ran parallel to the railroad tracks until it was decommissioned in 1985. The park has preserved within its boundaries a small grassy section of the road. Interstate 40, which crosses the park, replaced the older highway. 
Question: What is the name of the place that 60 BNSF trains pass through everyday?
Example Output: Petrified Forest.

Example Input: Passage: Dürer's father wears a dark shirt, russet coat and a black hat lined with fur. His skin is slack at the mouth and chin, and he has small, intelligent eyes, which Von Fircks describes as "dark and serious". Their curves echo those of the heavy lids beneath. His eyes are lined with crow's feet and shadowed with brown hatched paint. His facial features are built from brush strokes more typical of drawing than painting—at this young age Dürer was a far more skilled draughtsman than painter. Technical analysis carried out in 2013 by Dagmar Hirschfelder revealed a detailed background which was over-painted by the artist. The abandoned interior space consisted of a corner of a room with an arched window looking out to a countryside view. This type of interior can be traced to the Netherlandish tradition, and is rare in German portraiture of the period.
Albrecht the Elder's lips are thin and tightly pursed and his mouth is broad and down-turned, yet his features are those of a handsome man. Marcel Brion described him as appearing "mild and thoughtful", an impression reinforced by the uncomplicated design of the painting. This view is reinforced by the relative drabness or simplicity of his clothes, which seem intended to convey a reserved, ascetic piousness. Dürer presents his father more like a low-ranking  ecclesiastic than a tradesman: a calm, considerate and straightforward man dressed up in his best, albeit modest, clothes. After his father's death in 1502, Dürer wrote that Albrecht the Elder "passed his life in great toil and stern hard labour, having nothing for his support save what he earned with his hand for himself, his wife and his children ... He underwent manifold afflictions, trials and adversities. But he won just praise from all who knew him ... he was also of few words, and was a God-fearing man."Martin Conway describes the portrayal of a dignified man marked by a grave expression and deep "furrows ploughed by seventy years of labour and sorrow". Conway believed the strength of the portrait is in part achieved through Dürer's ability to convey this hardship, while at the same time presenting a man still imbued with traces of pride, and possessing "a kind old face". Noting the obvious affection between the father and son as well as the half smile of the older man, he wonders if that grin might have been born of Albrecht the Elder's satisfaction that his toil has been rewarded by a son of such talent, who was now about to set out on the world for his wanderjahr. A contributing factor to this pride is that Albrecht the Elder trained his son in his own profession, as a jeweller, but at one point came to regret the choice of apprenticeship as the younger man was so obviously suited to drawing and painting. However, his son learned many skills during that period and it gave him a discipline with his hands that became a defining factor of his work, especially in his ability as an engraver. 
Question: What is the name of the artist who over-painted the detailed background, which was revealed in technical analysis carried out in 2013?
Example Output:
Dürer.