Definition: In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: Did Olvir Hnufa's father die before his brother-in-law? Passage:Olvir Hnufa or Ölvir hnúfa was a Norwegian commander in a clan and poet of the late ninth and early tenth centuries, known from, among other sources, Egil's Saga, Skaldatal and the Prose Edda. Olvir was the son of the viking Berle-Kari and brother-in-law of Kveldulf Bjalfason, who married Olvir's sister Salbjorg Karadottir; he was thus uncle to Skallagrim and Thorolf Kveldulfsson and great uncle to the famous poet Egil Skallagrimsson. Olvir also had a brother named Eyvind Lambi. Olvir was a prominent member of the court of King Harald Fairhair, who united Norway under his rule in the late ninth or early tenth century. Among other famous poets, he served as one of King Harald's court poets. He also served as a warrior in Harald's retinue, and fought at the pivotal Battle of Hafrsfjord on the king's flagship. He is best known for his involvement in the conflict between Harald and Olvir's kinsman Thorolf Kveldulfsson, which ended with the latter's death. Only a few fragments of Olvir's poetry survive.


a