Final answer:
The correct defibrillator setting for treating ventricular tachycardia is to have synchronization set to OFF, as synchronization is typically used for rhythms where there is organized electrical activity and the shock needs to be timed to avoid the T wave.
Step-by-step explanation:
When treating a patient with ventricular tachycardia using a defibrillator, the appropriate setting is synchronization set to OFF (option C). This is because synchronization is only used for cardioversion, typically in situations where organized electrical activity is present (e.g., atrial fibrillation or supraventricular tachycardia), to ensure the shock is delivered in a way that avoids the vulnerable period of cardiac cycle (the T wave). Synchronizing to the T wave is dangerous and should be avoided because it can precipitate more dangerous cardiac arrhythmias. Synchronizing to the P wave or R wave is not relevant in this context and not typically how defibrillators are set for ventricular rhythms.