Question: The Ramsay state by-election occurred because of the resignation of which former Premier of South Australia?
Context: A by-election occurred in the South Australian House of Assembly seat of Ramsay on 11 February 2012.  The seat was won by Labor candidate Zoe Bettison.  The by-election was triggered by the resignation of former Premier and state Labor MHA Mike Rann. A by-election occurred for the New South Wales Legislative Assembly seat of Heffron on Saturday 25 August 2012.  This was triggered by the resignation of former Premier of New South Wales and state Labor MP Kristina Keneally which she announced on 23 June 2012.  Labor easily retained the seat with an increased margin.  Ron Hoenig received a 60 percent primary and 70 percent two-candidate preferred vote. The Norwood state by-election, 1980 was a by-election held on 16 February 1980 for the South Australian House of Assembly seat of Norwood.  It was triggered when the result in the seat at 1979 state election was overturned by the Court of Disputed Returns.  Created and first contested at the 1938 state election, the seat had been held by former Premier and Labor MHA Don Dunstan since the 1953 state election until his resignation.  The subsequent 1979 by-election was won by Labor's Greg Crafter, but he lost to the Liberal Party's Frank Webster at the 1979 state election. The Taylor state by-election, 1994 was a by-election held on 5 November 1994 for the South Australian House of Assembly seat of electoral district of Taylor, centred on Paralowie in the northern suburbs of Adelaide.  This was triggered by the resignation of former Premier and state Labor MHA Lynn Arnold on 21 September 1994.  The seat had been retained by Labor since it was created and first contested at the 1993 state election on a primary vote of 51.06 percent. The Goyder state by-election, 1974 was a by-election held on 8 June 1974 for the South Australian House of Assembly seat of Goyder.  This was triggered by the resignation of former Premier and Liberal and Country League/Liberal Movement MHA Steele Hall, who resigned to run for the Australian Senate at the 1974 federal election.  Created and first contested at the 1970 state election, the seat had been held by the Liberal parties since its creation.  Hall won the seat at the 1973 state election as an LCL candidate but afterward changed to the LM. The Barambah state by-election, 1988 was a by-election held on 16 April 1988 for the Queensland Legislative Assembly seat of Barambah, based in the town of Kingaroy.  The by-election was triggered by the resignation of National MP and former Premier Sir Joh Bjelke-Petersen.  Until the by-election, the seat had been considered the Nationals' safest seat in Queensland. Michael David "Mike" Rann , (born 5 January 1953) was the 44th Premier of South Australia from 2002 to 2011.  He accepted a professorship at Flinders University and a visiting fellowship at University of Auckland in 2012, was Australian High Commissioner to the United Kingdom from 2013 to 2014, and was Australia's Ambassador to Italy, Albania, Libya and San Marino and as Australia's Permanent Representative to the United Nation's Food and Agriculture Organisation and World Food Programme from 2014 to 2016.  Among several other honours, Rann was awarded the Companion of the Order of Australia (AC) at Australia Day in 2016. A state by-election was held in Queensland on 13 October 2007 to fill the vacancy in the Legislative Assembly of Queensland electoral district of Brisbane Central, formerly held by Labor member and former Premier Peter Beattie, who resigned on 14 September 2007.  The Liberal-National coalition failed to stand a candidate in the by-election.  A total of six candidates stood in the election. Patricia Lynne "Trish" White (born 7 September 1964) is a company director and former Australian politician, who represented Taylor in the South Australian House of Assembly for the Australian Labor Party.  She first won the seat at a state by-election held on 5 November 1994 following the retirement of former Premier Lynn Arnold and served for 16 years.  She was a senior cabinet minister in the Rann government. James Henry Griffin is an Australian politician.  He is a member of the New South Wales Legislative Assembly representing the electoral district of Manly for the Liberal Party of Australia.  Griffin was elected on 8 April 2017 at the Manly state by-election held to replace the previous member, former Premier of New South Wales Mike Baird.
Answer: Michael David "Mike" Rann