Final answer:
A political action committee sending out questionnaires to randomly-selected mailing addresses is employing survey research as their method to gather data on behaviors and opinions.
Step-by-step explanation:
The research method that a political action committee sending out a questionnaire to randomly-selected mailing addresses represents is a) Survey research. Surveys are utilized to collect data from subjects about their behaviors and opinions, and this is achieved through a series of questions provided in the form of a questionnaire. This method is widely used in various fields, including politics, to assess public opinion or gather feedback on certain issues. The committee conducting the survey would aim to obtain a random sample to ensure that the results are representative of the larger population, avoiding sampling error and ensuring the reliability and validity of the findings.