In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

[EX Q]: Question: How many people died in the incident that contaminated about 30,000 km?  Passage:Natural strontium is a mixture of four stable isotopes: Sr, Sr, Sr, and Sr. Their abundance increases with increasing mass number and the heaviest, Sr, makes up about 82.6% of all natural strontium, though the abundance varies due to the production of radiogenic Sr as the daughter of long-lived beta-decaying Rb. Of the unstable isotopes, the primary decay mode of the isotopes lighter than Sr is electron capture or positron emission to isotopes of rubidium, and that of the isotopes heavier than Sr is electron emission to isotopes of yttrium. Of special note are Sr and Sr. The former has a half-life of 50.6 days and is used to treat bone cancer due to strontium's chemical similarity and hence ability to replace calcium. While Sr (half-life 28.90 years) has been used similarly, it is also an isotope of concern in fallout from nuclear weapons and nuclear accidents due to its production as a fission product. Its presence in bones can cause bone cancer, cancer of nearby tissues, and leukemia. The 1986 Chernobyl nuclear accident contaminated about 30,000 km with greater than 10 kBq/m with Sr, which accounts for 5% of the core inventory of Sr.
 Links: a. Rubidium b. Mass number c. Electron capture d. Chernobyl disaster
[EX A]: d

[EX Q]: Question: To what city did the team that Olsen played with later move? Passage:Merlin Jay Olsen (; September 15, 1940 – March 11, 2010) was an American football player, announcer, and actor. He played his entire 15-year professional football career in National Football League (NFL) as a defensive tackle with the Los Angeles Rams. He was selected to the Pro Bowl a record 14 straight times, missing selection only in the last year of his career. This record of 14 seasons selected to play in the Pro Bowl, consecutive or otherwise, is shared with current New England Patriots quarterback Tom Brady, former offensive lineman Bruce Matthews, former tight end Tony Gonzalez, and former quarterback Peyton Manning. A recipient of the 1961 Outland Trophy as the best lineman in college football, Olsen is a member of the Pro Football Hall of Fame and the College Football Hall of Fame. As an actor, he portrayed farmer Jonathan Garvey on Little House on the Prairie. After leaving that series, he starred in his own NBC drama, Father Murphy.
 Links: a. NBC b. Los Angeles Rams c. Tom Brady d. American football
[EX A]: b

[EX Q]: Question: Which team finished ahead of Megan Cooke's team in the 2001 World Under-23 Championships? Passage:Cooke was on the rowing team at the University of California at Berkely, earning first team All-American honors twice along with first team All-Region and first team All-Pac accolades. She was the co-captain of the rowing team her junior and senior years, earning fourth place at the 2000 NCAA Championships and third place in the 2002. In 2001 she won a silver medal in the women's four without coxswain at the 2001 World Under-23 Championships. Cooke joined the U.S. National Team for rowing in 2004. Her last year on the national team was 2007. In 2006, as part of the U.S. World Champion women's eight, she helped set a world record for Team USA. She was also a 2006 Henley Royal Regatta champion and 2006 Head of the Charles Regatta champion. She won a silver medal in coxless pairs and a gold medal in the women's pair with partner Anna Mickelson at the 2006 World Rowing Cup in Lucerne. She placed fifth in the 2006 World Rowling Cup in Munich. Cooke competed in the 2006 FISA World Rowing Championships in Eton, helping her team win a gold medal with a world best time of 5:55.50. She was a silver medalist at the World Rowing Cup in Lintz. An injury in 2008 set Cooke back during the Senior Women's National Team's bids for the 2008 Summer Olympics. She retired from the U.S. National Team in 2008.
 Links: a. Eton, Berkshire b. Burnopfield c. Anna Mickelson d. World Rowing U23 Championships
[EX A]:
d