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: What is the tributary of the Croton River? Passage: the 1840s and 1850s the largest cities in the U.S. built pipelines to supply drinking water from rivers or lakes. However, the drinking water was initially not treated, since the link between waterborne pathogens and diseases was not yet well known. In 1842 New York City was one of the first cities in the U.S. to tap water resources outside the city limits. It dammed the Croton River in Westchester County, New York, and built an aqueduct from the reservoir to the city. Also in 1842, construction was completed on Chicago's first water works, with water mains made of cedar and a water intake located about into Lake Michigan. In 1848, Boston began construction of a water transmission system. A tributary of the Sudbury River was impounded creating Lake Cochituate, from where the Cochituate Aqueduct transported water to the Brookline Reservoir that fed the city's distribution system. In 1853 Washington, D.C. followed suit by beginning the construction of the Washington Aqueduct to provide water from the Great Falls on the Potomac River.


b