Question: Who won last triple crown of horse racing?
Disambiguated questions and answers: question: Which horse won the last triple crown of horse racing?
Which jockey won the last triple crown of horse racing?
Which trainer won the last triple crown of horse racing?
Which breeder won the last triple crown of  horse racing?
answer: Justify
Mike Smith
Bob Baffert
John D Gunther
Natural Questions answer: Justify (from the Wikipedia article "Triple Crown of Thoroughbred Racing (United States)")