Question: At the 2008 french open Katarina Srebotnik defeated an American professional tennis player who was born on what date?
Context: Katarina Srebotnik (born March 12, 1981) is a Slovenian professional tennis player.  She reached a career-high singles ranking of No. 20 on the Sony Ericsson WTA Tour on August 7, 2006, and a career-high doubles ranking of No. 1 on July 4, 2011. This list summarizes the main career statistics of Czech professional tennis player Lucie Šafářová.  To date, Šafářová has won seven WTA singles titles and fifteen WTA doubles titles including five Grand Slam doubles titles with Bethanie Mattek-Sands at the 2015 Australian Open and French Open,; the 2016 US Open and 2017 Australian Open and French Open.  Other highlights of Šafářová's career thus far include winning the 2015 Qatar Total Open, reaching the final of the 2015 French Open and making quarterfinal and semifinal appearances at the 2007 Australian Open and 2014 Wimbledon Championships, respectively.  Šafářová achieved career high singles and doubles rankings of World No. 5 and World No. 2 on 14 September 2015 and 30 January 2017. 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. Ernests Gulbis (] , born 30 August 1988, and nicknamed "The Gull" or "Ernie") is a Latvian professional tennis player.  In 2008, Gulbis won his first ATP Tour doubles title at the U.S. Men's Clay Court Championships, teaming with Rainer Schüttler, and in 2010 won his first ATP Tour singles title in the Delray Beach, defeating Ivo Karlović in the final.  In total, Gulbis has 6 ATP titles to his name and has never lost a final.  His best performance at a Grand Slam is reaching the semifinals of the 2014 French Open.  He had previously reached the quarterfinals of the 2008 French Open.  Gulbis' career-high singles ranking is world No. 10, making him the only Latvian tennis player ever to be ranked inside the top 10 in ATP Singles Ranking.  He achieved this in June 2014. Pam Teeguarden (born April 17, 1951) is a former American professional tennis player in the 1970s and 1980s, ranked in the top 20 from 1970–1975, according to "John Dolan's Women's Tennis Ultimate Guide", prior to computer rankings.  She won two Grand Slam Doubles Titles and was a quarter finalist in singles at the U.S. Open and The French Open.  Her father Jerry, a well known coach, helped Margaret Court win the coveted Grand Slam (all four Grand Slam titles in one year) in 1970 and Virginia Wade to her 1977 Wimbledon triumph.  Teeguarden was voted the "Most Watchable Player" based on play and appearance by a group of Madison Avenue advertising executives or "Mad Men" while playing at the US Open.  Teeguarden played in 19 consecutive US Opens, holding the record until Chris Evert played in 20.  She wore the first all black outfit in the history of tennis in 1975 at The Bridgestone Doubles Championships in Tokyo, starting a trend that is still popular today.  Teeguarden was the first woman tennis player signed by Nike.  She played on the victorious Los Angeles Strings Team Tennis team in 1981 and won the Team Tennis Mixed Doubles Division with Tom Gullikson in 1977; they were also runners-up in the league that year. This is a list of the main career statistics of Serbian professional tennis player, Ana Ivanovic.  Ivanovic won fifteen WTA singles titles including one grand slam singles title at the 2008 French Open and three WTA Tier I singles titles.  She was also the runner-up at the 2007 French Open and 2008 Australian Open and a semi-finalist at the 2007 Wimbledon Championships and 2007 WTA Tour Championships.  On June 9, 2008 Ivanovic became the world No. 1 for the first time in her career. Ana Isabel Medina Garrigues (] , ] ; born 31 July 1982) is a former Spanish professional tennis player, and current coach.  As a player she reached a career high WTA Tour ranking of No. 16 on 4 May 2009, and has won 11 singles titles and 28 doubles titles, including the 2008 French Open and 2009 French Open with Virginia Ruano Pascual.  Like many of her Spanish compatriots, she is a clay court specialist who grinds to win most of her rallies.  However, unlike most of her fellow Spaniards, she prefers to play on hard courts. This is a list of the main career statistics of retired, Russian professional tennis player, Dinara Safina.  Throughout her career, Safina won twelve WTA singles titles including three Tier I singles titles at the 2008 Qatar Telecom German Open, Rogers Cup and Toray Pan Pacific Open respectively; one Premier Mandatory singles title at the 2009 Mutua Madrileña Madrid Open and one Premier 5 singles title at the 2009 Internazionali BNL d'Italia.  She was also the runner-up at the 2008 French Open and the 2009 Australian Open and French Open as well as a silver medalist in singles at the 2008 Beijing Olympics. Justine Henin was the three-time defending champion, but she retired from the sport on May 14, 2008.  Her retirement left Serena Williams as the only former French Open champion remaining in the women's draw.  Williams was defeated in the third round by Katarina Srebotnik, meaning that there would be a first-time French Open champion in 2008. Ana Ivanovic (Serbian: Ана Ивановић, "Ana Ivanović" ; ] ; born 6 November 1987) is a retired Serbian tennis player.  She was ranked No. 1 in the world in 2008, after she had defeated Dinara Safina to win the 2008 French Open.  She was also the runner-up at the 2007 French Open and the 2008 Australian Open.  She also qualified for the annual WTA Tour Championships three times, in 2007, 2008 and 2014 and won the year-end WTA Tournament of Champions twice, in 2010 and 2011.
Answer: September 26, 1981