You are the first to arrive at the scene of a crash, and there is an injured person. the first thing you should do is

The correct answer to this open question is the following.

You are the first to arrive at the scene of a crash, and there is an injured person. The first thing you should do is park your car at a safe distance from the accident to asses if the situation is dangerous for you or not. If not, you carefully approach the scene of the accident, check if there is not gasoline spilled or fire, and then yo call 911. You then signal the accident with your traffic triangles and turn your hazard lights so other drivers can drive carefully if they decide to help and they can pull over.  If you can and the victim is conscious, you can offer help if there is no risk at all but remember, never, ever move the victim.