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.

Question: What was Montana's population the year that Thom Ross completed his work "Custer's Last Stand"? Passage:Ross' first plywood installation was a 1976 cutout of Clint Eastwood, which he and a friend placed as a prank above a railroad trestle to recreate a scene from Dirty Harry in the location where the scene had been filmed five years earlier. In 1983 Ross created "154 Nevermore", an installation of 154 plywood ravens on a highway in Jackson, Wyoming (recreated in steel in 2000). In 1984, Ross created "the Catch", a diorama for the Baseball Hall of Fame illustrating a legendary catch with the same nickname, by Willie Mays in the 1954 World Series. He created a new version of the work in 2004, and displayed it in various locations in New York City. In 1998 Ross created "The Defining Moment" for SAFECO Field, a tableau of 11 steel cutouts of a Ken Griffey, Junior play in the 1995 baseball playoffs. Ross' 2005 work, "Custer's Last Stand", was a recreation of life-sized warriors riding life-sized horses the Battle of Little Bighorn at the original site at Medicine Tail Coulee in Montana. That exhibit toured Cody, Wyoming, Jackson, Wyoming, and Sun Valley, Idaho. In September, 2008 Ross recreated a 1902 photograph of Buffalo Bill Cody and his "Wild West Show", his traveling troupe of Native Americans, in front of the Cliff House at Ocean Beach.
Links: a. National Baseball Hall of Fame and Museum b. Battle of the Little Bighorn c. Montana d. T-Mobile Park
c