Task: Text Categorization
Input (English): Context: The Oker is a river in Lower Saxony Germany that has historically formed an important political boundary. It is a left tributary of the River Aller 105 kilometres (65 mi) in length and runs in a generally northerly direction.
Question: The document can be classified to which topic? 
Options: 1)Film, 2)NaturalPlace, 3)OfficeHolder, 4)Company
Output (English): 2