31709
On 13 February 2015 , scientists ( including Geoffrey Marcy , Seth Shostak , Frank Drake and David Brin ) at a convention of the American Association for the Advancement of Science , discussed Active SETI and whether transmitting a message to possible intelligent extraterrestrials in the Cosmos was a good idea ; one result was a statement , signed by many , that a " worldwide scientific , political and humanitarian discussion must occur before any message is sent " .
 Geoffrey Marcy, Seth Shostak, Frank Drake, David Brin, American Association for the Advancement of Science
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Geoffrey Marcy, Seth Shostak, Frank Drake, David Brin, American Association for the Advancement of Science