Question: Who resigned as the Welsh Assembly Member for the North Wales region to represent Eddisbury in the House of Commons in the UK Parliament in 2015?

Context paragraphs:
Eddisbury (UK Parliament constituency): Eddisbury is a constituency in Cheshire represented in the House of Commons of the UK Parliament since 2015 by Antoinette Sandbach, a Conservative.

Ieuan Wyn Jones: Ieuan Wyn Jones (born 22 May 1949) is a Welsh politician who was the Deputy First Minister in the Welsh Assembly Government from 2007 to 2011.  He was the Member of the National Assembly for Wales for the Ynys Môn constituency from 1999 to 2013, and he was also leader of Plaid Cymru from 2000 to 2012.  Jones served as Member of Parliament for Ynys Môn constituency from 1987 to 2001, when he retired to focus on his work in the Welsh Assembly.  In 2007, Jones was named Wales' "Politician of the Year" by the BBC Wales am.pm programme.  He resigned from the Welsh Assembly on 20 June 2013.  In 2017 he unsuccessfully sought to return to the House of Commons for his former constituency.

List of Parliamentary constituencies in Clwyd: Seven constituencies cover Clwyd.  They are county constituencies (CCs) (for type of returning officer and election expenses) of the House of Commons of the UK Parliament (Westminster), and are used also for elections to the National Assembly for Wales.  The current boundaries have been effective since the Welsh Assembly election, 2007 and the 2010 United Kingdom general election.

Antoinette Sandbach: Antoinette Geraldine Mackeson-Sandbach (born 15 February 1969), known in politics as Antoinette Sandbach, is a Conservative Party politician who was elected as the Member of Parliament for Eddisbury at the 2015 general election.  The following day, 8 May 2015, she resigned as the Welsh Assembly Member for the North Wales region.  having been elected as a North Wales regional Assembly Member at the May 2011 election.

List of Parliamentary constituencies in Powys: Powys is divided into two constituencies of the House of Commons of the UK Parliament (Westminster), which are also used for elections to the National Assembly for Wales.  The current boundaries have been effective since the Welsh Assembly election, 2007 and the 2010 UK general election.

Brynle Williams: Brynle Williams (9 January 1949 – 1 April 2011) was a North Wales Assembly Member (AM) for the Welsh Conservative Party in the National Assembly for Wales.  Elected from the North Wales Regional list, he was Shadow Minister for Rural Affairs from 2007 to 2011.  Williams, who was a farmer from North Wales, was a colourful political figure who was respected for his straight talking and campaigning on rural issues; although privately he admitted he never saw himself as a politician.

Blaenau Gwent by-elections, 2006: Two by-elections were held for the constituency of Blaenau Gwent in Wales following the death of Member of Parliament and Assembly Member Peter Law on 25 April 2006.  As Law was the MP and Assembly Member (AM), his death required by-elections in both the parliamentary seat and the equivalent Welsh Assembly constituency.  The two elections polled on the same day, 29 June, as a by-election in Bromley and Chislehurst.  A win by the Labour Party in the AM by-election would have restored their majority in the Welsh Assembly, which was lost when Law was expelled from the party.

Llyr Huws Gruffydd: Llŷr Huws Gruffydd, (born 25 September 1970) is a Welsh Plaid Cymru politician, and a Member of the Welsh Assembly for the North Wales region.

Altaf Hussain (Welsh politician): Dr Altaf Hussain was a Welsh Conservative regional Assembly Member in the National Assembly for Wales from 2015 to 2016.  He is a retired consultant orthopaedic surgeon.  Prior to dissolution of the fourth assembly, he sat on the Health Committee at the National Assembly for Wales, and was Shadow Minister for Social Services.  He was defeated in the 2016 Welsh Assembly elections.  In 2017 he was elected to Bridgend County Borough Council.

Arfon (UK Parliament constituency): Arfon is a constituency of the House of Commons of the Parliament of the United Kingdom (at Westminster).  Although the constituency is relatively large by geographical area, it is a predominantly urban rather than rural seat, with the majority of the population living in the two towns on which the constituency is based, Bangor and Caernarfon.  "Arfon" is a historical name for the area, meaning "facing Anglesey"; it is also the name of the former district council.  This seat was created by the Welsh Boundary Commission in time for the 2010 general election, and replaced the old seat of Caernarfon.  Bangor was in the old seat of Conwy.  The same boundaries were used for the Arfon Welsh Assembly constituency in the 2007 Welsh Assembly election.

Supporting paragraphs: Eddisbury (UK Parliament constituency) Antoinette Sandbach
Answer: Antoinette Sandbach