Detailed Instructions: 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.
Q: Question: In what year was Isildur slain at Gladden Fields? Passage:Along with the Sceptre of Annuminas, the Star of Elendil was the chief symbol of the royal line of Arnor. The original jewel was fashioned of "elvish crystal" by the Noldor and affixed to a fillet of mithril, to be worn in the custom of Numenor on the brow in place of a crown. This was worn by Silmarien of Numenor and passed to her descendants, the Lords of Andunie, and eventually to Elendil. Elendil and then his son Isildur wore it as a token of royalty in the North Kingdom, but it was lost in the Anduin when Isildur was slain by orcs at the Gladden Fields. A replacement was fashioned by elves in Rivendell for Isildur's son Valandil, and this second jewel was borne by the subsequent thirty-nine kings and chieftains of Arnor, up to and including Aragorn.
Links: a. Middle-earth b. Middle-earth c. Gladden Fields d. Isildur
A:
c