Detailed Instructions: 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.
Problem:Question: Were the Oz books the only books L. Frank Baum ever wrote? Passage:The Land of Ev is a fictional country in the Oz books of L. Frank Baum and his successors. Its exact location is unclear between text and maps. The Road to Oz states that Ev is to the north of the Land of Oz, and in Ozma of Oz, Princess Ozma of Oz and her procession enter the Munchkin Country and meet the King of the Munchkins upon leaving the palace at Evna, the capital city. Subsequent books place Ev nearer to the Winkie Country, and the map on the endpapers of Tik-Tok of Oz shows the Munchkin Country as having no northern border with the desert that surrounds Oz, as a thin strip of the Gillikin Country extends even farther east than most of the Munchkin Country. This map depicts Ev as a small country to the northwest (the compass rose is reversed) of Oz, with the Dominions of the Nome King as a separate area. James E. Haff and Dick Martin's map, following the text, place the Nome Kingdom under an Ev that takes up the entire portion allotted to the Nome King's dominions on Baum's map.

Solution:
a