Macroeconomics focuses on the study of: O A. the costs and benefits of working in certain industries. O B. why people become unemployed for long periods. C. broad economic activities affecting entire countries. D. factors influencing individual families' economic behavior.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

they protect against unsafe foods and medicines being sold

explanation: