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.

Input: Consider 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

Output: c


Input: Consider Input: Question: Do more people live in Fauntleroy's birth place than the town where he died? Passage:Archibald Magill Fauntleroy (b. in Warrenton, Virginia, 8 July 1837; d. in Staunton, Virginia, 19 June 1886) was a physician. He graduated in medicine at the University of Pennsylvania in 1856, and in 1857 entered the United States Army as assistant surgeon; but, upon the start of the Civil War, he and his brother, a lieutenant in the navy, resigned at the same time with their father, Thomas T. Fauntleroy. He became a surgeon in the Confederate army, and was president of the board for the admission of surgeons, and chief officer on the medical staff of Gen. Joseph E. Johnston, and served with him until the battle of Seven Pines. He was then ordered to build and organize the hospitals at Danville, Virginia, and afterward had charge of the military hospital at Staunton, Virginia, until the war ended. He remained and practised at Staunton after the war, and was for several years superintendent of the lunatic asylum at that place. His contributions to medical literature include papers on potassium bromide, chloral hydrate, the use of chloroform in obstetrical practice, and a “Report upon Advance in Therapeutics,” which was printed in the Transactions of the Virginia Medical Society.
 Links: a. Warrenton, Virginia b. Battle of Seven Pines c. Chloral hydrate d. Staunton, Virginia

Output: a


Input: Consider Input: Question: Which of the players that were brought in to replace the departing players for the Cardinals was the oldest? Passage:The new season brought a Cardinals team that was much changed from the one that went 100-62 in 2005 but fell to the Houston Astros in the NLCS. Starting pitcher Matt Morris, second baseman Mark Grudzielanek, left fielder Reggie Sanders, and relief pitcher Julián Tavárez left the team via free agency. Relief pitcher Ray King was traded to Colorado. Right fielder Larry Walker retired. Brought in to replace the departed Cardinals were right fielder Juan Encarnación, starting pitcher Sidney Ponson, relief pitchers Braden Looper and Ricardo Rincón, all via free agency, and second baseman Aaron Miles, acquired in the Ray King trade. Left field was left unsettled in the offseason and would remain so all year, with no player getting more than one-third of the playing time at that position.
 Links: a. Juan Encarnación b. Houston Astros c. Ricardo Rincón d. Mark Grudzielanek


Output: a