Answer:
a. response bias.
Step-by-step explanation:
Response bias often referred to as Survey bias is a term in so cool psychology, in which an individual or subject in a research study, has probability or tendency to give response or answer to tests or assessment items in untruthful or misleading manner, such that, the response is socially acceptable rather than the truth response.
In other words, response bias occurs as result of people giving answer to survey questions in manners that do not correlates with their actual characteristics, such as attitudes, beliefs, thoughts, or behaviors.
Hence, in this case, many participants in the research study, were giving bias response, technically defined as Response Bias.