Question: Trent Zimmerman was elected to succeed a politician who is the current ambassador of Australia to which country ?

Context paragraphs:
Austria–Pakistan relations: Austria–Pakistan relations are the bilateral relations between Austria and Pakistan.  Pakistan maintains an embassy in Vienna, where the current Ambassador of Pakistan to Austria is Ayesha Riyaz, as well as a Honorary Consulate in Innsbruck.  Austria also has an embassy in Islamabad, where the current Ambassador of Austria to Pakistan and Afghanistan is Axel Wech.  There are Honorary Consulates in Karachi and Lahore as well.

China–Jamaica relations: Diplomatic relations between China and Jamaica were established on 21 November 1972.  The Chinese government established an embassy in Kingston in 1973.  There was no formal representation from Jamaica to China until 1992, when the Jamaican ambassador to Tokyo, Japan was accredited as a non-resident ambassador to Beijing.  Jamaica later established a formal embassy in Beijing, and the current ambassador is Courtenay Rattray.  The current Chinese ambassador to Jamaica is Chen Jinghua.  In 2007, China announced it would provide technical training for more than 2,000 Jamaicans in 2008.

Afghanistan–Tajikistan relations: Afghanistan–Tajikistan relations refers to the relations between the Islamic Republic of Afghanistan and the Republic of Tajikistan, which began in 1992.  Afghanistan maintains an embassy in Dushanbe and a consulate in Khorugh.  The current ambassador is Dr. Abdulghafour Arezou.  Tajikistan maintains an embassy in Kabul and a consulate in Mazari Sharif, Faizabad and Kunduz.  The current ambassador is Sharofiddin Imom.

Patricia Eugenia Cárdenas Santa María: Patricia Eugenia Cárdenas Santamaría (born 1 April 1958) is a Colombian diplomat, businesswoman and engineer.  She is the current Ambassador of Colombia in México.  In the past, she served as Ambassador of Colombia to Brazil, Ambassador of Colombia to Japan and Non-Resident Ambassador to Singapore, and the Non-Resident Ambassador to Australia and New Zealand.  An industrial engineer, she was President of the Banking and Financial Institutions Association of Colombia from 2000 to 2006.

Trent Zimmerman: Trent Moir Zimmerman (born 15 October 1968) is an Australian politician.  He was elected to succeed Joe Hockey as the Liberal Party of Australia member of the House of Representatives seat of North Sydney at the 2015 by-election.  Zimmerman is one of eight openly LGBTI current members of the Parliament of Australia and the first openly LGBTI member of the House of Representatives.

Joe Hockey: Joseph Benedict "Joe" Hockey (born 2 August 1965) is the current Ambassador of Australia to the United States.  He is a former Australian politician, the Member of Parliament for North Sydney from 1996 until 2015.  He was the Treasurer of Australia in the Abbott Government from 18 September 2013 until September 2015 when he resigned from Cabinet, having refused an alternative offer from the incoming Prime Minister, Malcolm Turnbull.  He previously served as the Minister for Human Services and Minister for Employment and Workplace Relations in the Howard Government.

List of Australian Ambassadors to Russia: The Ambassador of Australia to the Russian Federation is an officer of the Australian Department of Foreign Affairs and Trade and the head of the Embassy of the Commonwealth of Australia to the Russian Federation.  The position has the rank and status of an Ambassador Extraordinary and Plenipotentiary and holds non-resident accreditation for Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, Tajikistan, Armenia, Moldova and Belarus.  The current ambassador since January 2016 is Peter Tesch, who served from 1997–1999 as Ambassador to Kazakhstan.

China–Vanuatu relations: The Republic of Vanuatu and the People's Republic of China (PRC) established official diplomatic relations on March 26, 1982.  China established an embassy in Vanuatu in 1989, while Vanuatu established an honorary consulate in China in 1999; it officially became an embassy in 2005.  The current Ambassador of China in Vanuatu is Liu Quan.  The current Ambassador of Vanuatu in China is former Minister of Finance Willie Jimmy.

Austria–Turkmenistan relations: Austria–Turkmenistan relations are bilateral relations between Austria and Turkmenistan.  Turkmenistan maintains an embassy in Vienna, where the current Ambassador of Turkmenistan to Austria is Mr. Nurberdiyev Sylapberdi Ashyrgeldiyevich.  Austria has an embassy with residence in Astana (Kazakhstan) where the current Ambassador of Austria to Kazakhstan and Turkmenistan, Tajikistan, Kyrgyzstan is Mr. Wolfgang Banyai

Armenia–Turkmenistan relations: Armenian-Turkmen relations refers to the bilateral diplomatic relations between the Republic of Armenia and Turkmenistan.  Diplomatic relations on October 9, 1992.  Armenia is represented in has in Ashgabat, Turkmenistan, and Turkmenistan has its embassy in Yerevan.  The current Ambassador of Armenia to Turkmenistan is Vladimir Badalyan.  The current Ambassador of Turkmenistan to Armenia is Mukhamedniaz Mashalov.

Supporting paragraphs: Trent Zimmerman Joe Hockey
Answer: the United States