the trolley problem

The trolley problem: should you pull the lever to divert the runaway trolley onto the side track?

The trolley problem: should you pull the lever to divert the runaway trolley onto the side track?

Foot's original structure of the problem ran as follows:

Suppose that a judge or magistrate is faced with rioters demanding that a culprit be found for a certain crime and threatening otherwise to take their own bloody revenge on a particular section of the community. The real culprit being unknown, the judge sees himself as able to prevent the bloodshed only by framing some innocent person and having him executed.

The trolley problem is a thought experiment in ethics modeling an ethical dilemma. It is generally considered to represent a classic clash between two schools of moral thought, utilitarianism and deontological ethics. The general form of the problem is this:

There is a runaway trolley barreling down the railway tracks. Ahead, on the tracks, there are five people tied up and unable to move. The trolley is headed straight for them. You are standing some distance off in the train yard, next to a lever. If you pull this lever, the trolley will switch to a different set of tracks. However, you notice that there is one person on the side track. You have two options: 

Do nothing and allow the trolley to kill the five people on the main track.Pull the lever, diverting the trolley onto the side track where it will kill one person.

Which is the more ethical option? Or, more simply: What is the right thing to do?