Asurvey is a(n) a. unreliable and invalid research technique, usually used by magazines and political or commercial pollsters b. noncorrelational research technique for sampling a wide variety of populations c. experimental technique for sampling a population's attitudes d. research technique for assessing the behaviors and attitudes of a wide selection of people

A survey is a research technique for assessing the behaviors and attitudes of a wide selection of people.

A survey is one way for a company or organization to assess the behaviors and attitudes of a large group of people. By putting survey questions at the end of receipts or passing them out in public they are able to collect information from a large group that often do not connect with each other. 

Ithink the answer is d.