When are experiment targeting rules evaluated by default when an experiment is live?

 

When are experiment targeting rules evaluated by default when an experiment is live?

 

 A)  When the Optimize snippet script downloads and executes

 

 B)  On Pageview

 

 C)  On Window Load

 

 D)  On Visibility Change

 

https://www.youtube.com/watch?v=n0dy6hilm2Q