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: Which of the rivers along which Stephen traveled in 1376 has the widest point? Passage:Stephen was probably from the town of Ustiug. According to a church tradition, his mother was a Komi woman and his father was a Russian man. Stephen took his monastic vows in Rostov, where he learned Greek and learned his trade as a copyist. In 1376, he voyaged to lands along the Vychegda and Vym rivers, and it was then that he engaged in the conversion of the Zyriane (Komi peoples). Rather than imposing the Latin or Church Slavonic on the indigenous pagan populace, as all the contemporary missionaries did, Stephen learnt their language and traditions and worked out a distinct writing system for their use, creating the second oldest writing system for a Uralic language. Although his destruction of pagan idols (e.g., holy birches) earned him the wrath of some Permians, Pimen, the Metropolitan of All Rus', created him as the first bishop of Perm'. 


a