My vote? Superman rescues Lois as she is drifting off to her last sleep. But even though she sees Superman's bright costume and knows he's ripping her Jeep apart to get her free, she hears Clark's voice comforting her, feels Clark's arms cradle her, feels Clark fly her to the hospital.
Two days later - because her doctors have kept her sedated due to the extent of her injuries - Clark arrives to take her home and she starts putting the pieces together as he tells her how desperately Superman was searching for her. She figures "it" out but doesn't tell him she knows, then spends the rest of the day figuring out how to tell him.
And end it there, awaiting the followup challenge completion.
Unless there's another Lois from some other dimension waiting in the wings, you can't kill her off. Clark would be bereft forever. He might even seek some meager comfort in Mayson's arms (since this is after TOGOM but apparently before "Resurrection"), and wouldn't that just upset the universe's applecart?
