Ethics codes developed by psychologists urge investigators to: a. avoid the use of animals in experimental research. b. minimize the use of the double-blind procedure with human research participants. c. treat information about individual research participants confidentially avoid the use of financial incentives in any kind of research

Option (c) is correct

Explanation:

Code of ethics are the principles that are created by psychologist.These guidelines define about integrity ,confidentiality,honesty,etc. Research participant's information is considered as confidential according to investigator to maintain security and not disclosing it to external factors.

Other options are incorrect because using animals as participants, reducing double blind method or financial incentive use are not the factors that investigators take care of whole researching. Thus, the correct option is option(c).

it is due to the halo effect as the impression of the boy created earlier.on the mind of the principle affected his decision