Determine the type of bias involved. A researcher wants to know if a particular cereal helps lower cholesterol. The researcher selects a sample of 500 people with high cholesterol. He checks their cholesterol, asks them to eat the particular cereal for 30 days, and then come back to have their cholesterol checked again. 90% of the people who came back had lower cholesterol levels. 30 people came back to complete the study. bias. X 5 The type of bias involved in the given information is (Choose one) voluntary response social acceptability self-interest nonresponse