Definition: You are given a sentence, a question and two answer options ('A' and 'B'). Your task is to find the correct option for the given question. Write down the answer index: 'A' or 'B'.
Input: Sentence: An astronomer was studying the properties of some stars. She saw that one was a neutron star that was so densely packed with material that it had a far larger mass than an ordinary star that she was also observing. Question: Which of these stars would she expect to have a greater gravitational force? (A) neutron star (B) ordinary star
Output:
A