Question: Who is the sibling of the player who won the 2012 U.S. Open Men's Singles final?

Knowledge 1: 2012 US Open – Men's singles final
The 2012 US Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2012 US Open. In the final, Andy Murray defeated defending champion Novak Djokovic 7 -- 6, 7 -- 5, 2 -- 6, 3 -- 6, 6 -- 2 to win the match. It was the equal - longest US Open men's final in history, lasting 4 hours and 54 minutes (equalling the 1988 US Open final played by Ivan Lendl and Mats Wilander), and the equal second - longest men's final in the Open era, only behind the 2012 Australian Open final. By winning the 2012 US Open, Murray became the first British man since Fred Perry in 1936 to win a Grand Slam singles title, and the first British man in the Open Era to do so. The match is a significant part of the rivalry between the two players. This match also marked a milestone for Murray, as it was his 100th match win at a grand slam tournament. [SEP] Knowledge 2: 2011 Valencia Open 500 – Doubles
Andy Murray and Jamie Murray were the defending champions but decided to participate at Basel instead. The brothers Bob and Mike Bryan became the new champions, defeating Eric Butorac and Jean-Julien Rojer in the final.
Knowledge 1: 2012 US Open – Men's singles final
The 2012 US Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2012 US Open. In the final, Andy Murray defeated defending champion Novak Djokovic 7 -- 6, 7 -- 5, 2 -- 6, 3 -- 6, 6 -- 2 to win the match. It was the equal - longest US Open men's final in history, lasting 4 hours and 54 minutes (equalling the 1988 US Open final played by Ivan Lendl and Mats Wilander), and the equal second - longest men's final in the Open era, only behind the 2012 Australian Open final. By winning the 2012 US Open, Murray became the first British man since Fred Perry in 1936 to win a Grand Slam singles title, and the first British man in the Open Era to do so. The match is a significant part of the rivalry between the two players. This match also marked a milestone for Murray, as it was his 100th match win at a grand slam tournament. [SEP] Knowledge 2: US Open (tennis)
The US Open is held annually, starting on the last Monday in August, and lasting for two weeks into September, with the middle weekend coinciding with the Labor Day holiday. The main tournament consists of five event championships: men's and women's singles, men's and women's doubles, and mixed doubles, with additional tournaments for senior, junior, and wheelchair players. Since 1978, the tournament has been played on acrylic hard courts at the USTA Billie Jean King National Tennis Center in Flushing Meadows -- Corona Park, Queens, New York City. The US Open is owned and organized by the United States Tennis Association (USTA), a not - for - profit organization. Net proceeds from ticket sales, sponsorships, and television deals are used to promote the development of tennis in the United States.
Knowledge 1: 2012 US Open – Men's singles final
The 2012 US Open Men's Singles final was the championship tennis match of the Men's Singles tournament at the 2012 US Open. In the final, Andy Murray defeated defending champion Novak Djokovic 7 -- 6, 7 -- 5, 2 -- 6, 3 -- 6, 6 -- 2 to win the match. It was the equal - longest US Open men's final in history, lasting 4 hours and 54 minutes (equalling the 1988 US Open final played by Ivan Lendl and Mats Wilander), and the equal second - longest men's final in the Open era, only behind the 2012 Australian Open final. By winning the 2012 US Open, Murray became the first British man since Fred Perry in 1936 to win a Grand Slam singles title, and the first British man in the Open Era to do so. The match is a significant part of the rivalry between the two players. This match also marked a milestone for Murray, as it was his 100th match win at a grand slam tournament. [SEP] Knowledge 2: Australian Open
The Australian Open is a tennis tournament held annually over the last fortnight of January in Melbourne, Australia. First held in 1905, the tournament is chronologically the first of the four Grand Slam tennis events of the year -- the other three being the French Open, Wimbledon and the US Open. It features men's and women's singles; men's, women's and mixed doubles and junior's championships; as well as wheelchair, legends and exhibition events. Prior to 1988 the tournament had been played on grass courts, but since then two types of hardcourt surfaces have been used at Melbourne Park -- green coloured Rebound Ace up to 2007 and, afterwards, blue Plexicushion.

Answer: Jamie Murray