In intellectual discussions I pick 1, or it's variant (flip a coin). The reality is I flip the switch because pulling the lever is not much effort on my part compared to the outcome and in a situation truly this dire then I think utilitarianism is more informative. I don't think that gives a warrant for utilitarianism in all cases though; particularly because we don't have the foresight or a clear timescale to evaluate the consequences upon.
To illustrate this: put baby Hitler as one of the five people. Then increasingly advance the year of Hitler's age: at what point does the utilitarian run over Hitler and kill four innocents?