Question: The 1986 South Antrim by-election included a candidate from which Northern Irish unionist party?
Sentence (from "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.
Relevant evidence: No