Suppose that a software company using a freemium pricing model wants to generate annual revenue of $2 million. The company estimates that the average annual revenue per paying customer is $70 and that 3.5 percent of customers who use the free version of the software will purchase the upgraded version. How many paying customers must the company attract to reach its revenue goal? A. 28,571 B. 2,450 C. 816,314 D. 70,000 E. 57,142,857