Definition: In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it, i.e., the proper nouns in the passage. Your job is to determine whether information from more than one term is needed to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: How many grand slam tournaments did Steffi Graf win over her career? Passage:Graf lost an Australian Open quarterfinal to Jana Novotná, the first time she did not reach the semifinals of a Grand Slam singles tournament since the 1986 French Open. She then lost to Sabatini in her next three tournaments before winning the U.S. Hardcourt Championships in San Antonio, beating Monica Seles in the final. After losing a fifth straight time to Sabatini in Amelia Island, Florida, Graf again defeated Seles in the Hamburg final. Following her tournament victory in German Open in Berlin, Graf suffered one of the worst defeats of her career in a French Open semifinal where she won only two games against Sánchez Vicario and lost her first 6–0 set since 1984. At Wimbledon, however, Graf captured her third women's crown, this time at Sabatini's expense. Sabatini served for the match twice, and was two points away from her first Wimbledon title. After breaking Sabatini's serve to even the third set at 6–6, Graf defeated Sabatini by winning the next two games to take the match 6–4, 3–6, 8–6. Martina Navratilova then defeated Graf 7–6, 6–7, 6–4 in a US Open semifinal, the first time she had beaten Graf in four years. Graf then won in Leipzig, with her 500th career victory coming in a quarterfinal against Judith Wiesner. After winning two more indoor tournaments at Zurich and Brighton, she failed once again in the Virginia Slims Championships, losing her quarterfinal to Novotná. Soon after, she split with her long-time coach, Pavel Složil.


a