**Core Concept**
Talon's cusp is an anatomical feature of the heart, specifically a small, pointed projection on the right coronary cusp of the aortic valve. This characteristic is associated with a congenital heart defect.

**Why the Correct Answer is Right**
Talon's cusp is a hallmark feature of Ebstein's anomaly, a congenital heart defect characterized by an abnormal tricuspid valve and right ventricular hypoplasia. The presence of Talon's cusp is a key diagnostic criterion for Ebstein's anomaly, often seen in patients with this condition. The cusp is thought to arise from the abnormal development of the tricuspid valve leaflets.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because Talon's cusp is not a feature of Tetralogy of Fallot, a different congenital heart defect characterized by four main components: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta.
**Option B:** This option is incorrect because Talon's cusp is not a feature of Atrial Septal Defect (ASD), a type of congenital heart defect characterized by an abnormal opening in the atrial septum.
**Option C:** This option is incorrect because Talon's cusp is not a feature of Ventricular Septal Defect (VSD), a type of congenital heart defect characterized by an abnormal opening in the ventricular septum.
**Option D:** This option is incorrect because Talon's cusp is not a feature of Tricuspid Atresia, a congenital heart defect characterized by the absence or abnormal development of the tricuspid valve.

**Clinical Pearl / High-Yield Fact**
When evaluating a patient with suspected Ebstein's anomaly, remember to look for the characteristic "scooped-out" appearance of the right atrium and the presence of Talon's cusp on the right coronary cusp of the aortic valve.

**Correct Answer: A. Ebstein's anomaly**