Task: Text Categorization
Input (English): Context: Cidlina (Czech pronunciation: [ˈtsɪdlɪna]) is a river in the Czech Republic draining south from its source in Tábor hill near Lomnice nad Popelkou through Jičín Nový Bydžov and Chlumec nad Cidlinou merging with the Elbe (Labe) at Libice nad Cidlinou. Cidlina is 87.3 kilometers long its drainage area covers 1164 km² and average discharge is 4.66 m³/s.
Question: The document can be classified to which topic? 
Options: 1)MeanOfTransportation, 2)Artist, 3)OfficeHolder, 4)NaturalPlace, 5)Athlete
Output (English): 4