Dancing Grenade

Q. I repeat Dancing Grenade and it is the only spell on the chain. As it resolves, the controller chooses to pay 2[A] (via Repeat). Assuming it resolves and the next controller opts out, how many times would Ravenbloom Student trigger?

A. 3 times. Once for the initial spell, and then 2 more times when it is played again (and adds 2 more items to the chain).