Dr. Hite contacts women's groups throughout the state and wants to find out how many women have cheated on their husbands and how many are satisfied in their marriages. She sends out thousands of surveys and only 4% of all the women respond to the request. Dr. Hite finds a large number have cheated on their husband and almost all are unhappy in their marriage. She shares her findings, but there is a major flaw in her study? What is the flaw? interviewer bias participant observation nonresponse bias all of the above none of the above