24406
As at 21 May 2020 , Willis board under probe over merger agreement with Aon .
 location: Willis; organization: Aon
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: Willis, Aon 
Answer:
 location: Willis; organization: Aon