Alex the African grey parrot lived and was studied for 30 years before his death last year . His researchers taught him english and then tested his reasoning abilities . In one test Alex was presented with a tray on which lay a green key and a green cup .

Question: What may be the reason Alex the African Grey was appreciated in life ?
Answer: Researchers were able to learn much about how the mind of an older Macaw works .The knowledge that was gained by working with him is invaluable .Alex was able to teach his researchers much about birds in his 20 years of service .None of the above choices .