**Question:** True about V.S.D. is, all except

A. Ventricular septal defect (VSD) is a congenital heart defect where there is an opening between the ventricles of the heart.
B. It is a rare condition affecting only 1% of the population.
C. The shunt from the pulmonary artery to the oxygen-rich aorta is closed in VSD.
D. VSD is a type of arrhythmia.

**Correct Answer:** D. Ventricular septal defect (VSD) is not a type of arrhythmia, but rather a congenital heart defect characterized by an opening between the ventricles of the heart. VSD allows blood to bypass the lungs, resulting in a shunt from the pulmonary artery to the oxygen-rich aorta. Option D is incorrect because VSD does not cause arrhythmias, but rather affects cardiac output and oxygenation.

**Core Concept:** Ventricular septal defect (VSD) is a congenital heart defect characterized by an opening between the left and right ventricles of the heart, causing a shunt from the pulmonary artery to the aorta. This results in a reduction of blood flow to the lungs and increased oxygen-rich blood flow to the systemic circulation.

**Why the Correct Answer is Right:**

A. The correct answer (C) highlights the key aspect of VSD: It describes the shunt from the pulmonary artery to the oxygen-rich aorta, which is a result of the defect allowing blood to bypass the lungs. This is a crucial feature of VSD, as it affects cardiac output and oxygenation.

B. VSD affects a relatively small percentage of the population (1%). This information is relevant for understanding the prevalence of the condition but is not directly related to the correct answer.

**Why Each Wrong Answer is Incorrect:**

A. The incorrect option (A) misrepresents VSD as a rare condition affecting only 1% of the population. Although the prevalence is roughly 1%, the core concept of VSD remains the same.

B. VSD is not a type of arrhythmia (option D). Arrhythmias involve irregular heart rhythms, while VSD is a congenital heart defect characterized by an opening between the ventricles, affecting cardiac output and oxygenation.

**Core Concept Overview:**

VSD is a congenital heart defect that occurs during fetal development, affecting approximately 1% of the population. It results in an abnormal shunt of blood flow from the pulmonary artery to the aorta through an opening between the ventricles, leading to decreased pulmonary blood flow and increased oxygen-rich blood flow to the systemic circulation.

**Why the Correct Answer is Right:**

C. This option (C) emphasizes the key feature of VSD, which is the shunt from the pulmonary artery to the aorta due to the opening between the ventricles. This affects the oxygenation of blood and overall cardiac output.

**Why Each Wrong Answer is Incorrect:**

D. VSD is not an arrhythmia (option D). Arrhythmias involve