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: Leaders Launch Drive to Curb Polio in Africa  KANO, Nigeria (Reuters) - Political leaders and health  workers launched a drive Saturday to immunise more than 80  million children against polio in 23 African nations and fight  back against a resurgence of the crippling disease.

World