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: The independence of the ECB is instrumental in maintaining price stability. Not only must the bank not seek influence, but EU institutions and national governments are bound by the treaties to respect the ECB's independence. To offer some accountability, the ECB is bound to publish reports on its activities and has to address its annual report to the European Parliament, the European Commission, the Council of the European Union and the European Council. The European Parliament also gets to question and then issue its opinion on candidates to the executive board. Question: Why do EU institutions and national governments have to respect the independence of the ECB?
Example Output: bound by the treaties

Example Input: Passage: A elevator of this kind uses a vacuum on top of the cab and a valve on the top of the "shaft" to move the cab upwards and closes the valve in order to keep the cab at the same level. a diaphragm or a piston is used as a "brake" if there's a sudden increase in pressure avove the cab. however, to go down, it opens the valve so that the air can pressurize the top of the "shaft", allowing the cab to go down by its own weight. this also means that in case of a power failure, the cab will automatically go down. the "shaft" is made of acrilic, is always round, due to the shape of the vacuum pump turbine. in order to keep the air inside of the cab, rubber seals are used. due to technical limitations, these elevators have a low capacity. they usually allow 1-3 passengers and up to 525 lbs. Question: For sudden surges in pressure above the cab, what is used as a "brake"?
Example Output: a diaphragm or a piston

Example Input: Passage: Beyoncé further expanded her acting career, starring as blues singer Etta James in the 2008 musical biopic, Cadillac Records. Her performance in the film received praise from critics, and she garnered several nominations for her portrayal of James, including a Satellite Award nomination for Best Supporting Actress, and a NAACP Image Award nomination for Outstanding Supporting Actress. Beyoncé donated her entire salary from the film to Phoenix House, an organization of rehabilitation centers for heroin addicts around the country. On January 20, 2009, Beyoncé performed James' "At Last" at the First Couple's first inaugural ball. Beyoncé starred opposite Ali Larter and Idris Elba in the thriller, Obsessed. She played Sharon Charles, a mother and wife who learns of a woman's obsessive behavior over her husband. Although the film received negative reviews from critics, the movie did well at the US box office, grossing $68 million—$60 million more than Cadillac Records—on a budget of $20 million. The fight scene finale between Sharon and the character played by Ali Larter also won the 2010 MTV Movie Award for Best Fight. Question: Which thriller film did Beyoncé star in with Ali Larter?
Example Output:
Obsessed.