How do odysseus and his surviving men escape from the cave?

Athey lash themselves to rams and ride out when polyphemus opens the door.

Bthey ram an enormous olive tree trunk into the barrier and run out.

Cthey sneak out when the giant is drunk and asleep and has forgotten to cover the doorway.

Dthey sneak out when the other cyclopes come to check on the wounded polyphemus.