This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Example Input: Passage: Between 2000 and 2004 an average of 478 crimes were reported each day in Mexico City; however, the actual crime rate is thought to be much higher "since most people are reluctant to report crime". Under policies enacted by Mayor Marcelo Ebrard between 2009 and 2011, Mexico City underwent a major security upgrade with violent and petty crime rates both falling significantly despite the rise in violent crime in other parts of the country. Some of the policies enacted included the installation of 11,000 security cameras around the city and a very large expansion of the police force. Mexico City has one of the world's highest police officer-to-resident ratios, with one uniformed officer per 100 citizens. Question: What Mexican mayor tried to crack down on crime immensely? 
Example Output: Marcelo Ebrard

Example Input: Passage: A cover story in BusinessWeek magazine claims that economists mostly failed to predict the worst international economic crisis since the Great Depression of the 1930s. The Wharton School of the University of Pennsylvania's online business journal examines why economists failed to predict a major global financial crisis. Popular articles published in the mass media have led the general public to believe that the majority of economists have failed in their obligation to predict the financial crisis. For example, an article in the New York Times informs that economist Nouriel Roubini warned of such crisis as early as September 2006, and the article goes on to state that the profession of economics is bad at predicting recessions. According to The Guardian, Roubini was ridiculed for predicting a collapse of the housing market and worldwide recession, while The New York Times labelled him "Dr. Doom". Question: Which school at University of Pennsylvania examined in their online business journal why economists failed to predict the crisis?
Example Output: The Wharton School

Example Input: Passage: The most common forms of uranium oxide are triuranium octoxide (U
3O
8) and UO
2. Both oxide forms are solids that have low solubility in water and are relatively stable over a wide range of environmental conditions. Triuranium octoxide is (depending on conditions) the most stable compound of uranium and is the form most commonly found in nature. Uranium dioxide is the form in which uranium is most commonly used as a nuclear reactor fuel. At ambient temperatures, UO
2 will gradually convert to U
3O
8. Because of their stability, uranium oxides are generally considered the preferred chemical form for storage or disposal. Question: Along with UO2, what is the commonest form of uranium oxide?
Example Output:
triuranium octoxide