question: The attack on what city in Libya by members of the Islamic group Ansar al-Sharia led to the formation of a committee with Trey Gowdy as it's chairman?
answer: Benghazi
context: Title: 2012 Benghazi attack
  Passage: The 2012 Benghazi attack refers to a coordinated attack against two United States government facilities in Benghazi, Libya by members of the Islamic militant group Ansar al-Sharia.
  Title: Ansar al-Sharia (Yemen)
  Passage: Jama'at Ansar al-Shari'a (Arabic: جماعة أنصار الشريعة‎ ‎ ; "Jamāʿat Anṣār aš-Šharīʿa "), also known as Ansar al-Shari'a, is a Yemen-based umbrella organization which includes units from several militant Islamic groups of al-Qaeda in the Arabian Peninsula (AQAP).  In 2011, AQAP created Ansar Al-Sharia as a Yemen-based affiliate focused on waging an insurgency rather than international attacks on the West.  In the view of the International Crisis Group, AQAP is "an internally diverse organisation with varying layers of support among the local population" and many AAS members and allies are not committed to AQAP's international agenda.
  Title: Ansar al-Sharia (Mauritania)
  Passage: Ansar Al-Sharia fi Bilad Sinqit, better known as Ansar al-Sharia in Mauritania (English: Partisans of Islamic Law) is a radical Islamist group that operates in Mauritania.
  Title: United States House Select Committee on Benghazi
  Passage: The United States House Select Committee on Events Surrounding the 2012 Terrorist Attack in Benghazi was created after Speaker of the United States House of Representatives John Boehner, on May 2, 2014, proposed that a House select committee would be formed to further investigate the Benghazi attack on September 11, 2012.  During that event, the U.S. diplomatic mission in Benghazi, Libya was attacked, resulting in the deaths of the U.S. ambassador to that country, J. Christopher Stevens, and three other Americans.  On May 8, 2014, the House voted 232–186 to establish the select committee, with 225 Republicans and 7 Democrats in favor, and 186 Democrats voting against.  The chairman of the committee is Representative Trey Gowdy from South Carolina.
citations: 2012 Benghazi attack United States House Select Committee on Benghazi