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 grape is used to make the least wine in Mosel? Passage:Mosel is one of 13 German wine regions (Weinbaugebiete) for quality wines (Qualitätswein, formerly QbA and Prädikatswein), and takes its name from the Mosel River (. Luxembourgish: Musel.). Before 1 August 2007 the region was called Mosel-Saar-Ruwer, but changed to a name that was considered more consumer-friendly. The wine region is Germany's third largest in terms of production but some consider it the leading region in terms of international prestige. The region covers the valleys of the rivers Mosel, Saar, and Ruwer from near the mouth of the Mosel at Koblenz and upstream to the vicinity of Trier in the federal state of Rhineland-Palatinate. The area is known for the steep slopes of the region's vineyards overlooking the river. At 65° degrees incline, the steepest recorded vineyard in the world is the Calmont vineyard located on the Mosel and belonging to the village of Bremm, and therefore referred to as Bremmer Calmont. The Mosel is mainly famous for its wines made from the Riesling grape, but Elbling and Müller-Thurgau also contribute to the production, among others. In the past two decades red wine production, especially from the Spätburgunder (Pinot noir), has increased in the Mosel and throughout the German vignoble and has become of increasing interest to the international wine community. Because of the northerly location of the Mosel, the Riesling wines are often light, tending to lower alcohol, crisp and high in acidity, and often exhibit "flowery" rather than or in addition to "fruity" aromas. Its most common vineyard soil is derived in the main from various kinds of slate deposits, which tend to give the wines a transparent, mineralic aspect, that often exhibit great depth of flavor. In the current era of climate change much work has been done to improve and gain acceptance for completely dry ("Trocken") Rieslings in this region, so that most of the more famous makers have found acceptance for such wines, particularly in Europe.


b