Question: The 1986 South Antrim by-election included a candidate from which Northern Irish unionist party?

Context paragraphs:
South Antrim by-election, 1986: The 1986 South Antrim by-election was one of the fifteen 1986 Northern Ireland by-elections held on 23 January 1986, to fill vacancies in the Parliament of the United Kingdom caused by the resignation in December 1985 of all sitting Unionist Members of Parliament (MPs).  The MPs, from the Ulster Unionist Party, Democratic Unionist Party and Ulster Popular Unionist Party, did this to highlight their opposition to the Anglo-Irish Agreement.  Each of their parties agreed not to contest seats previously held by the others, and each outgoing MP stood for re-election.

East Antrim by-election, 1913: The East Antrim by-election of 1913 was held on 19 February 1913.  The by-election was held due to the death of the incumbent Irish Unionist MP, James McCalmont.  It was won by the Irish Unionist candidate Robert McCalmont, who was unopposed.

North Antrim by-election, 1986: The 1986 North Antrim by-election was one of the fifteen 1986 Northern Ireland by-elections held on 23 January 1986, to fill vacancies in the Parliament of the United Kingdom caused by the resignation in December 1985 of all sitting Unionist Members of Parliament (MPs).  The MPs, from the Ulster Unionist Party, Democratic Unionist Party and Ulster Popular Unionist Party, did this to highlight their opposition to the Anglo-Irish Agreement.  Each of their parties agreed not to contest seats previously held by the others, and each outgoing MP stood for re-election.

East Antrim by-election, 1919: The East Antrim by-election of 1919 was held on 27 May 1919.  The by-election was held due to the appointed commander of the Irish guards of the incumbent Irish Unionist MP, Robert Chaine Alexander McCalmont.  It was won by the Independent Unionist candidate George Boyle Hanna.

Mid Antrim by-election, 1915: The Mid Antrim by-election of 1915 was held on 17 February 1915.  The by-election was held due to the incumbent Irish Unionist MP, Arthur O'Neill, being killed in action in at Klein Zillebeke ridge during the First Battle of Ypres in the First World War.  It was won by his brother the Irish Unionist candidate Hugh O'Neill, who was elected unopposed.

Democratic Unionist Party: The Democratic Unionist Party is a unionist political party in Northern Ireland.

East Antrim by-election, 1986: The 1986 East Antrim by-election was one of the fifteen 1986 Northern Ireland by-elections held on 23 January 1986, to fill vacancies in the Parliament of the United Kingdom caused by the resignation in December 1985 of all sitting Unionist Members of Parliament (MPs).  The MPs, from the Ulster Unionist Party, Democratic Unionist Party and Ulster Popular Unionist Party, did this to highlight their opposition to the Anglo-Irish Agreement.  Each of their parties agreed not to contest seats previously held by the others, and each outgoing MP stood for re-election.

Irish Unionist Alliance: The Irish Unionist Alliance (IUA), also known as the Irish Unionist Party or simply the Unionists, was a unionist political party founded in Ireland in 1891 from the Irish Loyal and Patriotic Union to oppose plans for Home Rule for Ireland within the United Kingdom of Great Britain and Ireland.  The party was led for much of its existence by Colonel Edward James Saunderson and later by William St John Brodrick, Earl of Midleton.  In total, eighty-six members of the House of Lords affiliated themselves with the Irish Unionist Alliance, although its broader membership was relatively small.

Belfast East by-election, 1892: The Belfast East by-election of 1892 was held on 9 March 1892 after the incumbent Irish Unionist Party, Edward de Cobain, was expelled from the House of Commons of the United Kingdom after a criminal conviction.  It was retained by the Irish Unionist Party candidate Gustav Wilhelm Wolff.

Danny Kinahan: Daniel de Burgh Kinahan (born 14 April 1958) is a British politician from the Ulster Unionist Party, Member of Parliament for South Antrim and former member of the Northern Ireland Assembly for South Antrim.  In 2005 he was elected to Antrim Borough Council, and in June 2009 he was appointed to the South Antrim seat in the Assembly vacated by the resignation of David Burnside.

Supporting paragraphs: South Antrim by-election, 1986 Democratic Unionist Party
Answer: Democratic Unionist Party