I doubt B is plausible. The autopilot will only trim if the elevator is holding a force. It won't matter how fast the aeroplane is going, the AP will keep itself in trim. I doubt the 737 could accelerate so fast that the AP trim couldn't keep up. If the power comes off suddenly, the aeroplane will be in-trim for that speed, apart from the thrust couple. I wouldn't have thought that that would be so much that a bit of backstick wouldn't correct it; maybe a shallow descent but not a major dive.
Have a read of the Icelandair 757 GA incident at Oslo in 2002. Massive push-forward on stick to -49° and 250KIAS by the captain. Why would he do that? Illusions?