Which of the following is the best description of ROSC (Return of Spontaneous Circulation)?

Rationale: A. ROSC, or Return of Spontaneous Circulation, occurs when a patient who was in cardiac arrest regains an effective heartbeat and circulation. This is typically evidenced by the return of a palpable pulse, measurable blood pressure, and sometimes spontaneous breathing. Achieving ROSC is the primary goal of cardiopulmonary resuscitation (CPR) and advanced cardiac life support (ACLS). B. Elevated blood pressure and heart rate during resuscitation do not indicate ROSC; these could reflect ongoing stress, medications, or inadequate perfusion without true spontaneous circulation. C. Lack of response to medications indicates refractory cardiac arrest, not ROSC. ROSC is defined by the restoration of effective circulation, not unresponsiveness. D. While a patient may remain comatose after resuscitation due to hypoxic brain injury, ROSC refers specifically to the return of spontaneous circulation, not neurologic status.