how many variables and observations are there in the sample data set from the national longitudinal study of youth?

What is the american psychological association’s ethical principle of psychologists and code of conduct based upon? a. the work of a dozen world-renowned philosophers and ethical savants. b. the feedback of thousands of psychologists and their ethical struggles. c. the regulatory power and authority of the united states constitution. d. the hippocratic rules and guidelines of medical practitioners and surgeons. select the best answer from the choices provided a b c