You Pull Up to the Scene of a One-Car Motor

You pull up to the scene of a one-car motor vehicle collision and find a physician treating the patient. Which one of the following is the best way to initially communicate with the doctor?

A) "Thank you, doctor, you can go now; we will take over."
B) "Hello, we are EMTs. How can we help you, doctor?"
C) "We will be in the ambulance if you need us."
D) "The law requires you to let us handle the situation."