**Core Concept**
Synchronous cardioversion is a medical procedure used to restore a normal heart rhythm by delivering a controlled electric shock to the heart. It involves the use of a synchronized cardioverter-defibrillator, which is programmed to deliver a shock only when the patient's heart is in a specific phase of its electrical cycle, typically during the T-wave of the electrocardiogram (ECG).

**Why the Correct Answer is Right**
The goal of synchronous cardioversion is to convert a life-threatening abnormal heart rhythm, such as ventricular fibrillation or ventricular tachycardia, to a normal sinus rhythm. The shock is delivered during the T-wave to avoid causing further arrhythmias or cardiac arrest. This technique is often used in emergency situations, such as cardiac arrest, and requires close monitoring of the patient's ECG.

**Why Each Wrong Option is Incorrect**
* **Option A:** Asynchronous cardioversion, also known as unsynchronized cardioversion, is used in situations where the patient's ECG is not accessible or when the patient is not in a specific phase of the electrical cycle.
* **Option B:** Chemical cardioversion, also known as pharmacological cardioversion, uses medications to convert an abnormal heart rhythm to a normal sinus rhythm. This method is often used for atrial fibrillation or flutter.
* **Option C:** Transcutaneous pacing is a technique used to temporarily restore a normal heart rhythm by delivering electrical impulses through the skin to the heart. It is often used in patients with bradycardia or heart block.

**Clinical Pearl / High-Yield Fact**
Synchronous cardioversion is typically used in emergency situations, but it should only be performed by trained healthcare professionals in a controlled environment, such as a hospital or emergency department.

**Correct Answer:** None provided. Please provide the correct options for the question.