Final answer:
The first step is to call for police backup to secure the scene due to the potential danger of the knife. Once the scene is safe, emergency medical treatment can be provided to the individual.
Step-by-step explanation:
You arrive on the scene to find a 34-year-old male lying on the ground in a pool of blood with bright, red blood spurting from a large cut in his shirt sleeve and he is clutching a knife between his teeth.
The first action should be to make the scene safe before providing aid. The presence of a knife indicates potential danger, and personal safety is paramount in emergency situations.
Therefore, the correct response would be to call for police backup to ensure your safety and the safety of others. Once the scene is safe and secure, emergency medical treatment for the wound can proceed.