Task: Question Answering
Input (English): Based on the evidence available at the time, early models of the solar system stated that all objects in space orbited Earth. In the 16th century, an astronomer reevaluated the evidence and proposed a model of the solar system that is still in use. What part of this model corrected the mistake in previous solar system models?  
 (A) The Sun is at the center of this model. (B) Earth is the largest object in this model. (C) This model contains more than one star. (D) This model shows that Earth is stationary.
Output (English): A