Definition: In this task, you are given a news article. Your task is to classify the article to one out of the four topics 'World', 'Sports', 'Business', 'Sci/Tech' if the article's main topic is relevant to the world, sports, business, and science/technology, correspondingly. If you are not sure about the topic, choose the closest option. Note that URLs in the text have been replaced with [Link].
Input: Birdstone retired to stud Birdstone, who denied Smarty Jones the Triple Crown by beating him in the Belmont Stakes, has been retired from racing due to an ankle injury his connections announced Wednesday.

Sports