On March 1, Green went to Easy Car Sales to buy a car. Green spoke to a salesperson and agreed to buy a car that Easy had in its showroom. On March 5, Green made a $500 down payment and signed a security agreement to secure the payment of the balance of the purchase price. On March 10, Green picked up the car. On March 15, Easy filed the security agreement. On what date was the security interest perfected by filing? March 10 March 5 ooo March 1 March 15