Question: In regards to the athlete born on September 18, 1971, who directed a documentary about him in 2013?
Context: Joseph Edward ("Joe") Prince (born June 25, 1954) is a former American athlete born in San Rafael, California, and raised in East Palo Alto, California.  He ran track for the Cal Poly San Luis Obispo Mustangs.  He was the 1974 CCAA Conference 220 yard sprint champion and earned NCAA College Division All-America honors.  He is the subject of the 2008 documentary "Liberation Saturday", which is based on his autobiography. Mariana Avitia Martínez (born September 18, 1993 in Monterrey, Nuevo León) is an athlete from Mexico who competes in archery. Rory Bosio is an American athlete born in 1984.  She is specialized in ultra-trail runs and won 2013 and 2014 edition of Ultra-Trail du Mont-Blanc and Lavaredo Ultra-Trail in 2014. Lance Edward Armstrong (born Lance Edward Gunderson on September 18, 1971) is an American former professional road racing cyclist.  Armstrong is the 1993 professional world champion, and won the Tour de France a record seven consecutive times from 1999 to 2005.  However, in 2012, he was banned from sanctioned Olympic sports for life as a result of long-term doping offenses.  As part of those sanctions, all results going back to August 1998, including his seven Tour wins, were voided. Oleh Tverdokhlib (in Ukrainian Твердохліб Олег, November 3, 1969 in Dnipropetrovsk – September 18, 1995) was a Ukrainian athlete.  He was still an improving competitor at 400 metre hurdles when he was killed by electric shock while fixing wiring at his parental home in September 1995. Teddi King (September 18, 1929 – November 18, 1977) was an American jazz and pop vocalist.  Born Theodora King in Boston, Massachusetts on September 18, 1929, she won a singing competition hosted by Dinah Shore at Boston's Tributary Theatre, later beginning work in a touring revue involved with "cheering up the military in the lull between the Second World War and the Korean conflict."  Improving her vocal and piano technique during this time, she first recorded with Nat Pierce in 1949, later recording with the Beryl Booker trio and with several other small groups from 1954–1955 (recordings which were available on three albums for Storyville).  She then toured with George Shearing for two years beginning in the summer of 1952, and for a time was managed by the famed George Wein.  King later began performing for a time in Las Vegas. Marga Petersen (September 18, 1919 in Bremen – September 22, 2002 in Ottersberg) was a German athlete who competed mainly in the sprints. Riaan Schoeman (born September 18, 1989 in Vereeniging) is a South African swimmer who specializes in the Individual Medley and Freestyle events.  He is a multiple-time South African champion and record holder for the Individual Medley and Freestyle events.  Schoeman also competes in open water events and was victorious in the 2009 edition of the Midmar Mile.  His brother Henri Schoeman is also an athlete, winning bronze in the 2016 Summer Olympics triathlon. William John "Billy" Sherring (September 18, 1877 – September 5, 1964) was a Canadian athlete of English and Irish descent, winner of the marathon race at the 1906 Intercalated Games (or 1906 Olympic Games, as they were at the time considered to be). The Armstrong Lie is a 2013 American documentary film directed by Alex Gibney about the cyclist Lance Armstrong.  Originally titled "The Road Back", the film takes its name from ""Le Mensonge Armstrong"", the headline of the August 23, 2005 issue of the French newspaper "L'Équipe".  The film was screened out of competition at the 70th Venice International Film Festival and in the Special Presentation section at the 2013 Toronto International Film Festival.
Answer: Alex Gibney