You respond to a farm for a possible snake bite. You find a​ 36-year-old male patient seated against a tree. Bystanders state the patient was bitten on the arm by a rattlesnake and is​ "really sick." As you​ approach, you notice that the patient is in obvious​ distress, diaphoretic, and holding his right wrist. Which of the following is your highest​ priority?

A. Immediately apply a constricting band to minimize the spread of the venom.
B. Confirm the type of snake and contact medical control for specific instructions.
C. Ensure the snake is no longer a threat.
D. Perform a primary assessment and identify any potential life threats.