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?

Context paragraphs:
Ansar al-Sharia (Tunisia): Ansar al-Sharia in Tunisia (""Supporters of Islamic Law in Tunisia"") is a radical Islamist group that operates in Tunisia.  It has around 1,000 people as part of the movement.  It has been listed as a terrorist group by the Tunisian government as well by the United Nations, the UAE, the United Kingdom and the United States.  Some of its members may be linked to the 2015 Sousse attacks.

Operation Dignity Battle (Benghazi): The Operation Dignity Battle was a battle of the Libyan Civil War of 2014.  It was fought in May and July 2014 between the Islamic Fundamentalist Shura Council of Benghazi Revolutionaries (supported by the LROR and Misrata Brigades) and the Libyan Army, and some people stand with Army into the city.  The Shura Council of Benghazi Revolutionaries led by Ansar al-Sharia (Libya) have been designated as a terrorist organization by the United Nations, Turkey, the UAE, the United Kingdom and the United States.

Ansar al-Sharia (Mauritania): 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.

2012 Benghazi attack: 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.

Ansar al-Sharia (Yemen): 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.

Ansar al-Sharia: Ansar al-Sharia or Ansar al-Shariah is a name used by a collection of radical or militant Islamist groups or militias, in at least eight countries.  While they share names and ideology, they lack a unified command structure.

Ansar al-Sharia (Derna, Libya): Ansar al-Sharia is the Derna based branch of a larger Libyan group; the branch is headed by Abu Sufian bin Qumu.  In 2011 bin Qumu became the leader of a band of fighters in his hometown of Derna during the 2011 Libyan civil war.  The group was reported as disbanding itself following the U.S. Consulate attack in Benghazi however by late 2013 the group had re-emerged in the city as a branch of the Benghazi-based Ansar al-Sharia under the slogan "A step toward building the Islamic state".

Ansar al-Sharia (Libya): Ansar al-Sharia in Libya (ASL, English: Supporters of Islamic Law) was a Salafist Islamist militia group that advocated the implementation of strict Sharia law across Libya.  Ansar al-Sharia came into being in 2011, during the Libyan Civil War.  Until January 2015, it was led by its "Amir", Muhammad al-Zahawi.  As part of its strategy, the organization targeted specific Libyan and American civilians for death and took part in the 2012 Benghazi attack.  The group was designated as a terrorist organization by the United Nations, Turkey, the UAE, the United Kingdom, and the United States.

Ansar al-Sharia (Egypt): al-Taliah al-Salafiyah al-Mujahediyah Ansar al-Sharia (English: Fighting Salafist Vanguard - Partisans of Islamic Law), better known by the name Ansar al-Sharia (Egypt), is a radical Islamist group that operates in Egypt.

United States House Select Committee on Benghazi: 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.

Supporting paragraphs: United States House Select Committee on Benghazi 2012 Benghazi attack
Answer: Benghazi