The correct option is D) The design of the study suffers from selection bias.
Explanation:
In research, Selection Bias occurs when the researcher decides who the respondents are or those who are being evaluated or studied.
Every research ought to be designed in such a way that the respondents are selected at random.
In the information provided, the respondents were selected from a group of people who on a balance of probability were already inclined to decline because it was a list of dissatisfied customers. The chances of them declining to respond or responding with a negative were higher than the chances of them indicating that they would buy and this defeats the purpose of the research. The research ought to have also included a sample of respondents who didn't have the product, who had enjoyed the services of the company and were content, those who didn't even know what the product did until they got the survey.
That way holistic information can be obtained from the research about how different sets of people will react and not just those who are already dissatisfied with the company's product(s).
Some of the ways to avoid selection bias in research are:
To employ the use of random techniques selecting sample sets from populations.To check that the traits or characteristics of the larger population are well represented in the samples selectedCheers