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.

Example Input: Question: How often are new issues of the Canadian Journal of Neurological Sciences published? Passage:Multi-dose versions of the vaccine contain the preservative thiomersal (also known as thimerosal), a mercury compound that prevents contamination when the vial is used repeatedly. Single-dose versions and the live vaccine do not contain this preservative. In the U.S., one dose from a multi-dose vial contains approximately 25 micrograms of mercury, a bit less than a typical tuna fish sandwich. In Canada, different variants contain five and 50 micrograms of thimerosal per dose. The use of thiomersal has been controversial, with claims that it can cause autism and other developmental disorders. The U.S. Institute of Medicine examined these claims and concluded in 2004 that the evidence did not support any link between vaccines and autism. Other reviews came to similar conclusions, with a 2006 review in the Canadian Journal of Neurological Sciences stating that there is no convincing evidence to support the claim that thimerosal has a causal role in autism, and a 2009 review in the journal Clinical Infectious Diseases stating that claims that mercury can cause autism are "biologically implausible". The U.K. National Health Service stated in 2003 that "There is no evidence of long-term adverse effects due to the exposure levels of thiomersal in vaccines." The World Health Organization concluded that there is "no evidence of toxicity in infants, children or adults exposed to thiomersal in vaccines". Indeed, in 2008 a review noted that even though thiomersal was removed from all US childhood vaccines in 2001, this has not changed the number of autism diagnoses, which are still increasing.
Links: a. Thiomersal and vaccines b. Autism c. Canadian Journal of Neurological Sciences d. National Academy of Medicine
Example Output: c

Example Input: Question: What city was Jet Ski Lady's last race in? Passage:Jet Ski Lady (foaled 20 February 1988) was an American-bred, Irish-trained thoroughbred racehorse, best known for winning The Oaks in 1991. In a racing career which lasted from June 1990 to October 1991 the filly ran ten times and won four races. After winning twice as a two-year-old, Jet Ski Lady competed against colts with mixed success in early 1991 before winning the Classic Oaks over one and a half miles at Epsom Downs Racecourse. Her winning margin of ten lengths was the second-widest in the race's history and her starting price of 50/1 made her the equal longest-priced winner of the Oaks on records. She subsequently finished second in both the Irish Oaks at the Curragh and the Yorkshire Oaks at York. She was retired to stud after finishing unplaced in the Prix de l'Arc de Triomphe.
Links: a. Yorkshire Oaks b. Colt (horse) c. Prix de l'Arc de Triomphe d. Filly
Example Output: c

Example Input: Question: When was the firm that designed the Oregon library established? Passage:The Oregon Library was designed by Chicago architects Pond and Pond. The Ponds were members of the Eagle's Nest Art Colony, founded by Lorado Taft, and their association with Taft and the colony led them to design the library. Their design was influenced by the colony, and a combination of two architectural styles, Classical Revival and the Arts and Crafts movement. The completed library included a second floor art gallery to which members of Eagle's Nest donated works for a permanent collection. The gallery's collection includes 64 paintings and sculptures as well as a Currier and Ives lithograph collection appraised at US$700,000. The Oregon Public Library was listed on the U.S. National Register of Historic Places in 2003, three years later it was included as a contributing property in a historic district that received the National Register designation.
Links: a. Eagle's Nest Art Colony b. Neoclassical architecture c. Arts and Crafts movement d. Pond and Pond
Example Output:
d