A manager of a department store uses an executive information system (EIS) to look at product sales over the last three quarters. Namely, for each product, how much of a product was in inventory, in what month did the product sell the most, and what type of products were sold the most over the three quarters. In general, why is the manager using the EIS? a. To track inventories. b. To spot trends. c. To look at logistics. d. To look at the backlog