How did Gutenberg's printing press improve upon existing printing methods?

Which of the following is an example of how the principle of beneficence can be applied to a study employing human subjects? providing detailed information about the study and obtaining the subject's consent to participate. ensuring that the selection of subjects includes people from all segments of the population. ensuring that persons with diminished autonomy are protected. determining that the study has a maximization of benefits and a minimization of risks.