Which of the Following Best Illustrates One of the Uses

Which of the following best illustrates one of the uses of marketing research,monitoring marketing performance?

A) marketing research managers closely overseeing the work of subordinates in the marketing research industry
B) tracking research that monitors how well products are performing in the marketplace
C) describing the return on investment of firms using/not using marketing research
D) providing closed circuit TV to monitor the actions of marketing researchers practicing in the field
E) identifying opportunities and problems in the marketplace