38447
This appeared to be confirmed by the exploration of the deep sea beds conducted by the Challenger expedition , 1872 – 1876 , which showed that contrary to expectation , land debris brought down by rivers to the ocean is deposited comparatively close to the shore on what is now known as the continental shelf .
 person: Challenger
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Challenger 
Answer:
 person: Challenger