John loans $500 to Mary, who John considers a “sketchball.” To ensure that John will receive his money back, he wants to have a perfected security interest in Mary's bicycle.  At what point would John have a perfected security interest in the bicycle?

1. Once John files a financing statement covering the bicycle.

2. Once John files a financing statement covering the bicycle and Mary signs an agreement confirming that she owes John $500.

3. Once Mary signs a security agreement covering the bicycle.

4. Once Mary signs a security agreement covering the bicycle and John files a financing statement covering the bicycle.