In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.

Input: Consider Input: Question: Why did the Nok culture die off about 200 AD on the Jos Plateau? Passage:The Nok culture thrived from approximately 1,500 BC to about 200 AD on the Jos Plateau in north and central Nigeria and produced life-sized terracotta figures that include human heads, human figures, and animals. Iron smelting furnaces at Taruga, a Nok site, date from around 600 BC. The Nok culture is thought to have begun smelting iron by 600-500 BC and possibly some centuries earlier. Kainji Dam excavations revealed iron-working by the 2nd century BC. Evidence of iron smelting has also been excavated at sites in the Nsukka region of southeast Nigeria in what is now Igboland: dating to 2,000 BC at the site of Lejja (Uzomaka 2009) and to 750 BC and at the site of Opi (Holl 2009). The transition from Neolithic times to the Iron Age apparently was achieved indigenously without intermediate bronze production. Others have suggested that the technology moved west from the Nile Valley, although the Iron Age in the Niger River valley and the forest region appears to predate the introduction of metallurgy in the upper savanna by more than 800 years. The earliest iron technology in West Africa has also been found to be contemporary with or predate that of the Nile valley and North Africa, and some archaeologists believe that iron metallurgy was likely developed independently in sub-Saharan West Africa.


Output: b


Input: Consider Input: Question: Where did the scientist Nash completed his postdoctoral research with attend college? Passage:Born in Exeter, England, and grew up in Sudbury, Ontario, Canada. In high school he competed in the Canada-Wide Science Fair in five successive years (1983–87), winning awards on each occasion and becoming one of the most highly awarded science fair participants in the history of the fair. In recognition of this he was selected to represent Canada as one of two youth delegates to the 1985 Nobel Prize lectures and ceremony in Stockholm, Sweden as part of the Stockholm International Youth Science Seminar and was awarded the International Youth Year Ontario Gold Medal. He received a BSc with honours in biochemistry from the University of Guelph, and the Chemical Institute of Canada prize for the top of class. He received a PhD in 1999 from the University of Alberta working in the laboratory of Dr. Grant McFadden investigating poxviral immunomodulatory proteins. His doctoral thesis focused on the enzymology and biological properties of the Myxoma virus encoded serine proteinase inhibitor (serpin), SERP-1. He completed postdoctoral research with Anthony Pawson at the Samuel Lunenfeld Research Institute of Mount Sinai Hospital and the University of Toronto from June 1999 to December 2003. In 2014, Nash received an MBA with a concentration in finance awarded with high honors from the University of Chicago Booth School of Business.


Output: b


Input: Consider Input: Question: Which of the two festivals where McCartney was scheduled to headline has existed longer? Passage:On 15 February 2016, McCartney announced two initial festival dates in Europe for the upcoming summer. These two headlining performances at Pinkpop Festival in Landgraaf, Netherlands and Rock Werchter in Werchter, Belgium were revealed before the initial revelation of the "One on One" tour. These tours would feature mostly similar elements of the "One on One" performances yet with a condensed set list to allot for festival curfew limits and less stage elements given restrictions. In the wake of the passing of notable Beatles and McCartney producer George Martin, McCartney announced the initial "One on One" dates for North America and Europe. In North America, McCartney's visit to Fresno, California would mark his first performance in the city, and his performances in North Little Rock and Sioux Falls would be his first performances in the states of Arkansas and South Dakota respectively. Elsewhere in North America, McCartney would perform in Portland after an eleven-year absence following his 2005 'US' tour. The two shows in Vancouver would follow his previous performance in the city at the BC Place stadium in 2012, yet this tour would feature two shows in the neighboring Rogers Arena after the pyrotechnics during his concert at BC Place accidentally damaged the stadium's new roof. McCartney's Seattle show would mark his shortest absence from any North American city on the tour announced currently, as he performed at the city's Safeco Field during the inaugural year of the 'Out There' tour. McCartney announced a performance on 16 March in Minneapolis at the Target Center. This show would take place on 4 May 2016, less than two years after McCartney's last performance in the city at the adjacent baseball stadium sharing a corporate sponsor with the arena, Target Field. Due to high demand of tickets a second show in Minneapolis was announced the next day and would take place on 5 May.



Output: b