Select the correct answer: What are customer insights? a$)$A text file inserted by a website sponsor into a Web surfer$$s hard drive that allows the site to track the surfer$$s moves

b$)$ A means to record traces of physical evidence that remain after people have consumed something

c$)$ The extent to which the results of a research study can be generalized to the population its sample was intended to represent, providing a higher level of confidence that the findings can be applied outside of the setting where the research was conducted

d$)$ The collection, deployment, and interpretation of information that allow a business to acquire, develop, and retain its customers