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: UPDATE 1-Strike ballots sent to UAL flight attendants-union The Association of Flight Attendants on Thursday mailed 21,000 strike authorization ballots to flight attendants at United Airlines, setting the stage for a work stoppage if the bankrupt airline repeals a collective bargaining 

Business