I thought MC = ATC in the long-run equilibrium for a perfectly competitive good, can someone explain to me how to do this question?

The top table shows the market demand schedule for DVDs and the bottom table shows the cost structure of each firm. Price Quantity demanded (dollars per DVD) (DVDs per week) The market for DVDs is perfectly competitive. There are 100 identical firms, and each firm's 8.00 total fixed costs are $200 a week. 30,000 8.50 25,500 In long-run equilibrium, what is the number of firms in the market and what is the market 9.00 20,000 price of a DVD? 9.50 15,000 10.00 10,000 . . . Marginal Average total In long-run equilibrium, the number of firms in the market is and the market price of Quantity cost cost a DVD is (DVDs per week) (dollars per DVD) 50 8.50 12.25 *A. 50; $10.00 100 9.00 10.50 O B. 150; $8.50 150 9.50 10.08 200 10.00 10.00 O C. 100; $9.50 250 10.50 10.05 XD. 200; $10.00