Following return of spontaneous circulation, the patient remains apneic. The EMT should:

In a patient who has returned to spontaneous circulation but remains apneic, it is critical to provide adequate ventilation to support their oxygenation and prevent hypoxia. Ventilating at 12 breaths per minute is within the acceptable range for adult patients, which generally recommends a rate of 10 to 12 breaths per minute in a controlled ventilatory setting. This rate allows for effective gas exchange and helps maintain optimal levels of oxygen saturation.

Maintaining an oxygen saturation of 95% to 99% is also crucial in this scenario, as it ensures that the tissues and organs receive enough oxygen for metabolic processes, especially following an event such as cardiac arrest. Adequate oxygen levels can help mitigate potential brain injury and promote recovery.

Other options may not correctly align with the appropriate clinical guidelines for ventilation following resuscitation. For instance, ventilating at too high a rate could lead to inadequate ventilation or hyperventilation. Similarly, aiming for an oxygen saturation of 100% can sometimes be excessive unless warranted by specific circumstances, as maintaining slightly lower saturation levels is generally sufficient and safer for preventing oxygen toxicity. Therefore, the correct choice prioritizes both effective ventilation and optimal oxygen saturation levels.