110242
Though issued in June 1926 , this specification did not reach a decision on the final engine to be used until October 1927 ; prototype contracts were only placed in January 1928 , and the four chosen manufacturers did not produce prototypes for trial until 1929 .
 None
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:  
Answer:
 None