You respond to the scene of an assault, where a 20-year-old man was struck in the chest with a steel pipe. Your assessment reveals that the patient is unresponsive, apneic, and pulseless. The MOST appropriate next intervention is to:

A. give 2 minutes of 15 compressions and 2 breaths.
B. look for evidence of a pericardial tamponade.
C. immediately assess the patient's cardiac rhythm.
D. perform 5 cycles of well-coordinated CPR.