Each decides to take a penalty stroke and drop back, in the fairway, on the line from the hole through their ball. Except the guy in the bunker doesn't get to do it. If he is a poor bunker player, under the Rules of Golf, he could quite literally never get out unless he opts to re-play his tee shot (stroke and distance), effectively a two-stroke penalty while the other players only suffer a one-stroke penalty.
What's the harm? Bunkers suck. Most players will continue to play out of them most of the time, but if your ball buries under the lip and you want to take an unplayable, why should you be penalized MORE than if your ball buries in the mud of a creek in a water hazard by having to play from the hazard again?
Good post, very interesting thoughts being bounced around. To clarify, the "mud of a creek" would be a water hazard and thus the unplayable is not an option to the golfer, only the guy hitting into the brush and the bunker have the unplayable option.
For the golfer in the brush, a lot of times the options B and C will result in a shot that is no better, they will still be in the dirt or blocked by trees etc, the only benefit they get is a clean swing at the ball, this is the same benefit given to golfer in the bunker, a clean swing from a normal lie.
I like the rule as it forces people to live with the fact that they hit into a bunker, there is no way out except to replay the shot which is a risk/reward decision.