Customers enter the type of pastry or sandwich they are going to have, and the app provides suggestions for the kind of coffee that is best suited to pair with their meal. In an email to the software development team, identify what type of research method is likely to produce the best results for testing the app: a survey, focus group, interview, observation, or field trial, explain how the research method can be applied in this matter and why it will be effective in yielding useful results.