charlie the store manager at a restaurant, conducts market research to collect data on the menu items most preferred by customers. based on his findings, he modifies the menu and adjust the prices of the items that customers are more likely to order. he believes that the chane he has made will increase the profitably of the restaurant. in the given scenario, charlie's belief reflects the _____ of marketing research. A. diagnostic role b. descriptive role c. prescriptive role d. predictive role