The answer is probably A but it could be all of them.
I just really want points
Answer:mental life; observable behavior
Explanation: Mental life has a lot to do with how psychologists focus more on the physiological research in the 1920s and 1960s, but as times goes by, they emphasize more on observable behavior. Because both mental life and observable behavior work together for a good psychological result.
<span>An expert is someone who expends the least amount of energy for the greatest result.
We call a person an expert if he performs really perfectly as compared to the newcomers because he is highly trained and professional and has the abilities to a specific art. Expertise is usually measured on the basis of intelligence and activeness together. Experts can never be seen unconfident in doing their job.
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