Question: Who was India's No. 1 player in both singles and doubles before their retirement, Frederik Nielsen or Sania Mirza?

full_context: Document 1: Goran Ivanišević: Goran Ivanišević (; born 13 September 1971) is a retired Croatian professional tennis player and current tennis coach. He is the only person to win the men's singles title at Wimbledon as a wildcard. He achieved this in 2001, having previously been runner-up at the championships in 1992, 1994 and 1998. Before the 2001 tournament, he was ranked 125th and after his victory he was 16th. His career-high singles ranking was World No. 2 (behind Pete Sampras) in 1994. He coached Marin Čilić from September 2013 to July 2016, leading Čilić to his biggest achievement to date, the 2014 US Open title.
Document 2: Leoš Friedl: Leoš Friedl (born 1 January 1977 in Jindřichův Hradec) is an inactive Czech professional tennis player best known for his doubles play with František Čermák. He is coached by Lubomir Gerla. During his career, Friedl won 16 top-level doubles titles and the 2001 Wimbledon mixed doubles title with Daniela Hantuchová, where they beat Mike Bryan and Liezel Huber, 4–6, 6–3, 6–2.
Document 3: 2012 Wimbledon Championships – Men's Doubles: Bob Bryan and Mike Bryan were the defending champions, but lost to wildcards Jonathan Marray and Frederik Nielsen in the semifinals. Marray and Nielsen won the title defeating fifth seeded Robert Lindstedt and Horia Tecău who competed in their third consecutive Wimbledon final. Marray became the first British player to win the men's doubles at Wimbledon since Pat Hughes and Raymond Tuckey in 1936. Nielsen is only the second Danish winner of a Grand Slam title, following his own grandfather, Kurt Nielsen, who won the mixed doubles at the 1957 U.S. National Championships.
Document 4: Roger Federer junior years: Swiss tennis player Roger Federer's main accomplishments as a junior player came at Wimbledon, where, in 1998, he won both the singles tournament over Irakli Labadze, in straight sets, and the doubles with Olivier Rochus, over the team of Michaël Llodra and Andy Ram, also in straight sets. In addition, Federer was a runner-up at the US Open Junior tournament in 1998, losing the final to David Nalbandian. Federer would go on to win four other junior singles tournaments in his career.
Document 5: Serena Williams: Serena Jameka Williams (born September 26, 1981) is an American professional tennis player. The Women's Tennis Association (WTA) has ranked her world No. 1 in singles on eight occasions, from 2002 to 2017. She became the world No. 1 for the first time on July 8, 2002. On the sixth occasion, she held the ranking for 186 consecutive weeks, tying the record set by Steffi Graf for the most consecutive weeks as world No. 1 by a female tennis player. In total, she has been world No. 1 for 319 weeks, which ranks her third in the Open Era among female tennis players. Some commentators, players and sports writers regard her as the greatest female tennis player of all time.
Document 6: Martina Hingis: Martina Hingis (born 30 September 1980) is a Swiss professional tennis player, a former world No. 1 singles player and currently ranked world No. 2 in doubles by the WTA. She has spent a total of 209 weeks as the singles No. 1 and has won five Grand Slam singles titles, thirteen Grand Slam women's doubles titles, winning a calendar-year doubles Grand Slam in 1998, and seven Grand Slam mixed doubles titles; for a combined total of twenty-five major titles. In addition, she has won the season-ending WTA Championships two times in singles and three times in doubles, and an Olympic silver medal.
Document 7: Daniel Nestor: Daniel Mark Nestor {'1': ", '2': ", '3': ", '4': "} (Serbian Cyrillic: Данијел Несторовић; born September 4, 1972 as Danijel Nestorović) is a Canadian professional tennis player. He is one of the foremost doubles players in tennis history due to his longevity and continued success at the top of the men's game. s of 2016 , he is 11th for most men's ATP titles in Open Era history. In January 2016, Nestor became the first doubles player in ATP history to win 1000 matches.
Document 8: Li Na: Li Na (; ; born 26 February 1982) is a retired Chinese professional tennis player, who achieved a career-high WTA-ranking of world No. 2 on 17 February 2014. Over the course of her career, Li won seven WTA singles titles and two Grand Slam singles titles at the 2011 French Open and 2014 Australian Open. Li's rise to prominence came after those victories, which made her the first and only Grand Slam singles champion from East Asia and Asia as a whole. Prior to this, she had already become the first player representing an East Asian and Asian country to appear in a Grand Slam singles final, a milestone she achieved at the 2011 Australian Open. Li was also the runner-up at the 2013 Australian Open and 2013 WTA Tour Championships, a three-time quarterfinalist at Wimbledon and a semifinalist at the 2008 Beijing Olympic Games and 2013 US Open. Among her other most notable accolades, she was the first Chinese player to win a WTA tour title at the Guangzhou International Women's Open in 2004, the first to reach a Grand Slam singles quarterfinal at the 2006 Wimbledon Championships, and the first to break into the world's top 10. Her feats have sparked a major population growth of tennis players in East Asia, earning her the reputation as the region's tennis pioneer and trailblazer.
Document 9: Frederik Nielsen: Frederik Løchte Nielsen (born 27 August 1983) is a professional male tennis player. He is a former Wimbledon Men's Doubles champion, in 2012, and now competes mainly on the ATP Challenger Tour in both singles and doubles. Nielsen is coached by fellow Dane John Larsen and is a member of the Denmark Davis Cup team. His grandfather is former grand slam finalist Kurt Nielsen.
Document 10: Lindsay Davenport: Lindsay Ann Davenport Leach (born June 8, 1976) is an American former professional tennis player. She was ranked World No. 1 on eight different occasions, for a total of 98 weeks. Davenport is one of five women who have been the year-end World No. 1 at least four times (1998, 2001, 2004, and 2005) since 1975; the others are Chris Evert, Steffi Graf, Martina Navratilova and Serena Williams. She has achieved the No. 1 ranking in doubles as well.
Document 11: Saina Nehwal: Saina Nehwal (   ; born 17 March 1990) is an Indian professional badminton singles player. She is one of the greatest players of her time. Nehwal, the former world no. 1 has won over twenty one international titles, which include ten Superseries titles. Although she reached to the world no. 2 ranking in 2009, it was only in 2015 that she was able to attain the world no. 1 ranking. And thereby becoming the only female player from India and overall the second Indian player – after Prakash Padukone – to achieve this feat. She has represented India three times in the Olympics, winning bronze medal in her second appearance.
Document 12: Fred McNair: Frederick V. McNair IV (born July 22, 1950 in Washington, D.C.) is a former professional tennis player from the United States who reached the World No. 1 doubles ranking in 1976. That year, he teamed up with Sherwood Stewart to capture the men's doubles titles at French Open, the German Open and the Masters. McNair was also a mixed doubles runner-up at the French Open in 1981, partnering Betty Stöve. In 1978, he was a member of the US team that won the Davis Cup. In nine years on the professional tour, McNair won 16 doubles titles. His career-high singles ranking was World No. 67.
Document 13: Peng Shuai: Peng Shuai (; ; born 8 January 1986) is a Chinese professional female tennis player. She reached a career high ranking of World No. 1 in doubles by the Women's Tennis Association on 17 February 2014, making her the first Chinese professional tennis player (male or female, and in singles or doubles) to reach World No. 1. She won a gold medal at the 2010 Asian Games, defeating Akgul Amanmuradova in the final. At the 2013 Wimbledon Championships, Peng won her first ladies' double championship with Hsieh Su-wei of Taiwan and again won at the 2014 French Open with Hsieh.
Document 14: 2013 Wimbledon Championships – Men's Doubles: Jonathan Marray and Frederik Nielsen were the defending champions, but decided not to play together. Marray played alongside Colin Fleming, but lost to Robert Lindstedt and Daniel Nestor in the third round. Nielsen paired up with Grigor Dimitrov, but lost to Julien Benneteau and Nenad Zimonjić in the second round.
Document 15: Sania Mirza: Sania Mirza (] ; born 15 November 1986) is an Indian professional tennis player who was formerly ranked No. 1 in the women's doubles rankings. From 2003 until her retirement from singles in 2013, she was ranked by the Women's Tennis Association as India's No. 1 player, both in singles and doubles. Throughout her career, Mirza has established herself as the most successful female Indian tennis player ever and one of the highest-paid and high-profile athletes in the country.
ground_truth: Sania Mirza