Which statement correctly distinguishes String: static from a static reference?

Which statement correctly distinguishes String: static from a static reference?

1. An owned String satisfies a static type bound but can still be dropped at the end of an ordinary block.
2. Any String satisfying the bound is stored in the program binary forever.
3. A reference to a local String becomes static when moved into a closure.
4. The static bound delays all destructors until process exit.